มาตรฐานการทดสอบวัสดุงานทาง กรมทางหลวงชนบท

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ 4. °“√√“¬ß“π §à“°“√¬ÿ∫μ—«¢ÕߧÕπ°√’μ ∑’ˉ¥â„À⮥‡ªìπ√“¬ß“π·≈– √ÿªº≈‡ªìπ‡´π쑇¡μ√ ∑»π‘¬¡ 1 μ”·Àπàß ≈ß„π·∫∫øÕ√塇≈¢∑Ë’ ∫ø. ¡∂.(∑) 103.1-2550 : «‘∏’°“√∑¥ Õ∫§à“°“√¬ÿ∫μ—«¢Õß §Õπ°√’μ 5. ‡°≥±°å “√μ¥—  π‘ ·≈–§«“¡§≈“¥‡§≈ÕË◊ π∑’ˬա„Àâ 5.1 §“à °“√¬∫ÿ μ—«¢ÕߧÕπ°√’μ„À‡â ªπì ‰ªμ“¡∑°Ë’ ”À𥉫„â πμ“√“ß ¥ß— π’È ™π¥‘ ¢Õßß“π°Õà  √“â ß §“à °“√¬ÿ∫μ—« (´¡.)  Ÿß ¥ÿ μ“ÌË  ¥ÿ ∞“π√“° 7.5 5 ·ºπà æ◊πÈ , §“π, ºπ—ß §. .≈. 10 5 ‡ “ 1122.5.5 5 §√∫’ §. .≈. ·≈–ºπ—ß∫“ßÊ 15 5 6. ¢âÕ§«√√–«ß— 6.1 °“√∑¥ Õ∫À“§à“°“√¬∫ÿ μ—«¢ÕߧÕπ°√μ’ ®–‰¡‡à À¡“–°—∫°“√«¥— º≈§“à ¬ÿ∫μ—«¢ÕߧÕπ°√μ’ „π °√≥’∑Ë«’ — ¥ÿº ¡¡«≈À¬“∫∑Ë„’ ™â¡’¢π“¥‡°π‘ 2 π‘«È ¢÷Èπ‰ª À√Õ◊ °√≥∑’ ’˧Õπ°√μ’ ·Àßâ ‡°‘π‰ª 6.2 „π°“√°√–∑ÿßâ §Õπ°√μ’ ∑¥ Õ∫„π·∫∫πÈ—π §«√°√–∑ÿâß„À∑â «Ë— ∫√‘‡«≥∑’ËÀπ“â μ—¥ ·≈–§«√°√–∑ßÿâ ∫√‘‡«≥¢Õ∫¢Õß·∫∫„Àâ‡∫“°«à“¿“¬„π ‡æË◊ÕªÑÕß°—π¡‘„Àâ·∫∫‡ ’¬À“¬‡πË◊Õß®“°°√–·∑°°—∫ ‡À≈Á°°√–∑ÿßâ 7. Àπß—  ◊ÕÕ“â ßÕ‘ß a. AMERICAN SOCIETY OF TESTING AND MATERIALS ; ASTM STANDARD : C 143-78 b. ¡“μ√∞“πº≈‘μ¿≥— ±åÕÿμ “À°√√¡ ¡Õ°. 213-2520 : §Õπ°√μ’ º ¡‡ √Á® À¡«¥ß“π‚§√ß √â“ß·≈–ª∞æ’«»‘ «°√√¡ 1-41

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ ‚§√ß°“√ÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇ. ∫∫øø..¡¡∑∂∂.(.(∑∑))110033.1.1--2255500 ∑–‡∫’¬π∑¥ Õ∫ÇÇÇÇÇÇ ÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇ  ∂“π∑’Ë°àÕ √â“ßÇÇÇÇÇÇÇÇÇÇÇÇ.. (Àπ૬ߓπ∑’Ë∑Ì“°“√∑¥ Õ∫) ºŸâ∑¥ Õ∫ ÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇ... °“√∑¥ Õ∫§à“°“√¬ÿ∫μ—«¢ÕߧÕπ°√’μ ºŸâμ√«® Õ∫ ºŸâ√—∫®â“ßÀ√◊ÕºŸâπÌ“ àßÇÇÇÇÇÇÇÇÇÇÇ Õπÿ¡μ— ‘ ™π‘¥μ—«Õ¬à“ß..ÇÇÇ.Ç.∑¥ Õ∫§√—Èß∑’ËÇÇÇ ((SSLluUmMpP TeEsStT)) ∑¥ Õ∫«—π∑’ËÇÇÇÇÇÇÇ.·ºàπ∑’ËÇÇÇÇ √–¬–§«“¡ Ÿß¢ÕߧÕπ°√’μ∑’Ë∑¥ Õ∫À≈—߬°·∫∫ÕÕ°(H) ÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇ.. ‡´π쑇¡μ√ §“à °“√¬∫ÿ μ«— ¢ÕߧÕπ°√’μ (SLUMP) = 30-H ‡´π쇑 ¡μ√ = ÇÇ.ÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇ ‡´π쇑 ¡μ√ À¡“¬‡Àμÿ : À¡“¬‡Àμÿ : 1-42 À¡«¥ß“π‚§√ß √“â ß·≈–ª∞æ«’ ‘»«°√√¡

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ ¡∂.(∑) 103.2-2550 ¡“μ√∞“π°“√∑¥ Õ∫À“§“à °“√¬ÿ∫μ«— ¢ÕߧÕπ°√’μ‚¥¬„™‚â μ–ä °“√‰À≈ (Flow Table) 1. ¢Õ∫¢à“¬ ¡“μ√∞“π°“√∑¥ Õ∫πÈ’ §√Õ∫§≈ÿ¡∂ß÷ °“√∑¥ Õ∫À“§“à °“√‰À≈¢ÕߧÕπ°√’μ 2. «‘∏∑’ ” 2.1 ‡§√ËÕ◊ ß¡◊Õ ª√–°Õ∫¥â«¬ 2.1.1 ·∫∫ (Mold) ∑”¥«â ¬‚≈À–¡≈’ °— …≥–‡ªπì √Ÿª°√«¬μ—¥ ∞“π¢Õß·∫∫¡’‡ âπºà“π»πŸ ¬°å ≈“ß 254 ¡‘≈≈‘‡¡μ√ (10 πÈ‘«)  à«πμ—¥μÕπ∫π¡’‡ âπºà“π»Ÿπ¬å°≈“ß 171 ¡‘≈≈‘‡¡μ√ (6 3/ π‘È«) 4 ¡’§«“¡ Ÿß 127 ¡‘≈≈‘‡¡μ√ (5 πÈ‘«) ª≈“¬∑—Èß Õߢâ“ßμâÕ߇ªî¥ÕÕ°‡ªìπ√–¬–μ—Èß©“°°—∫ ·π«»πŸ ¬å°≈“ߢÕß√Ÿª°√«¬ μ—«·∫∫®–μÕâ ß¡’¡Õ◊ ®—∫ Õߢ“â ßÕ¬àŸ∑Ë ’ «à π∫π 5é 1/ é 2 3/8é 10 é 18 Ì 6 3/ é 4 π‘È« 3/8 1/ 5 6 3/ 2 4 ¡¡. 9.5 12.7 127 171.5 ·∫∫ (Mold) °“√∑¥ Õ∫§“à °“√¬∫ÿ μ—«¢ÕߧÕπ°√’μ‚¥¬„™‚â μä–°“√‰À≈ 2.1.2 ‚μä–°“√‰À≈ ¡’≈—°…≥–¥—ß√Ÿªμ«— ‚μä–®–μÕâ ߬÷¥μ¥‘ °—∫∞“π§Õπ°√’μ∑Ë¡’ —Ëπ§ß·¢ßÁ ·√ß §◊Õ  Ÿßª√–¡“≥ 381-508 ¡‘≈≈‘‡¡μ√ (15-20 πÈ‘«) ·≈–¡’πÈ”Àπ—°‰¡àπâÕ¬°«à“ 135 °‘‚≈°√—¡ (300 ªÕπ¥å) À¡«¥ß“π‚§√ß √“â ß·≈–ª∞æ’«»‘ «°√√¡ 1-43

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ π«‘È 1/32 1/16 1/14 1/8 1/6 1/4.4 1/4 1/3.2 1/2.56 1/2.1 1/2 1.8 1.6 ¡¡. 0.8 1.6 1.9 3.2 3.9 5.9 6.4 7.9 9.9 11.9 12.7 13.9 15.9 π‘«È 1/14 1 1 1/2.3 1 1/8 2 2 1/2.7 3 1/2.5 3 1/2 3 1/1.6 7 1/4 12 17 30 ¡¡. 19.1 25.4 36.5 39.7 50.8 60.3 85.7 88.9 92.1 184.2 305 432 76.4 2.1.3 ‡À≈°Á °√–∑ßÿâ (Tamping Rod) ‡ªπì ·∑ßà ‡À≈°Á °≈¡ ¢π“¥‡ πâ ºà“π»Ÿπ¬å°≈“ß 16 ¡‘≈≈‡‘ ¡μ√ (5/8 π«È‘ ) ¬“« 610 ¡≈‘ ≈‘‡¡μ√ (24 πÈ«‘ ) ª≈“¬¥â“π∑„Ë’ ™°â √–∑ÿßâ ¡’≈—°…≥–¡π 2.2 ·∫∫øÕ√¡å „π°“√∫—π∑÷°º≈°“√∑¥ Õ∫ „™â·∫∫øÕ√å¡ ∫ø. ¡∂.(∑) 103.2-2550 : «‘∏’°“√∑¥ Õ∫ §à“°“√¬ÿ∫μ—«¢ÕߧÕπ°√μ’ ‚¥¬„™‚â μä–°“√‰À≈ 2.3 °“√‡μ√¬’ ¡μ«— Õ¬“à ß μ—«Õ¬à“߉¥â·°à§Õπ°√’μ´Ë÷ß·∫àß¡“®“°§Õπ°√’μº ¡‡ √Á® ‚¥¬º ¡¡“®“°‚√ßß“πÀ√◊Õ √∂º ¡§Õπ°√’μ À√◊Õ§Õπ°√’μ®“°‚¡à„πÀπâ“ß“π μâÕß欓¬“¡‡°Á∫®“°À≈“¬ à«π¢Õß‚¡à ·≈«â ®ß÷ π”¡“º ¡„À‡â ªìπ‡πÕÈ◊ ‡¥¬’ «°—π‡æËÕ◊ ∑”°“√∑¥ Õ∫ 2.4 °“√∑¥ Õ∫ 2.4.1 «“ß·∫∫≈ß°≈“ß‚μä–°“√‰À≈ ‚¥¬„™∞â “π¥“â π°«â“ßÕ¬àŸ¥â“π≈à“ß (‡ πâ ºà“π»Ÿπ¬°å ≈“ß 254 ¡‘≈≈‡‘ ¡μ√) 1-44 À¡«¥ß“π‚§√ß √â“ß·≈–ª∞æ«’ »‘ «°√√¡

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ 2.4.2 „ à§Õπ°√’μ∑Ë’®–∑”°“√∑¥ Õ∫≈ß„π·∫∫ª√–¡“≥ 1 „π 2 ¢Õߪ√‘¡“μ√¢Õß·∫∫ „™â ‡À≈°Á °√–∑âÿß °√–∑ßâÿ „Àâ∑Ë«— º‘«¢ÕߧÕπ°√μ’ „π·∫∫ ®”π«π 25 §√—ßÈ 2.4.3 ∑”μ“¡«∏‘ ’ ¢Õâ 2.4.2 Õ°’ §√—Èß „π≈—°…≥–‡¥’¬«°—π „Àâ§Õπ°√’μ‡μÁ¡·∫∫ª“¥º‘«∫π„Àâ ‡√¬’ ∫ ·≈⫬°·∫∫¢πÈ÷ „π·π«¥ßË‘ 2.4.4 ª√∫— ‚μä–°“√‰À≈ (Flow Table) ¥«â ¬¡◊ÕÀ¡πÿ „À¬â °¢÷πÈ ≈ß ≈—∫°—π‰ª„π·π«¥Ë‘ß ‚¥¬ ¡’√–¬–μà“ߢÕߧ«“¡ Ÿßª√–¡“≥ 12.7 ¡‘≈≈‘‡¡μ√ (1/2 πÈ‘«) 欓¬“¡À¡ÿπ¡◊ÕÀ¡ÿπ ∑’ˬ° ‚μä–∑¥ Õ∫¥â«¬§«“¡‡√Á« ¡Ë”‡ ¡Õ ®”π«π 15 §√—Èß ¿“¬„π√–¬–‡«≈“ª√–¡“≥ 15 «‘π“∑’ «—¥√–¬–∑Ë’§Õπ°√’μ∑¥ Õ∫·ºà°√–®“¬ÕÕ° ‚¥¬§‘¥§à“‡©≈’ˬ®“°√–¬–‡ âπºà“π »Ÿπ¬°å ≈“ß∑Ë«’ ¥— ‰¥â 6 ∑»‘ ∑“ß 3. °“√§”π«≥ §à“°“√‰À≈¢ÕߧÕπ°√’μ∑Ë’∑¥ Õ∫ ®–°”À𥇪ìπ√âÕ¬≈– ∑’ˇæ‘Ë¡¢÷Èπ¢Õß√–¬–‡ âπºà“π »πŸ ¬å°≈“ß∑·Ë’ ºÕà Õ°®“°∞“π §à“√Õâ ¬≈–¢Õß°“√‰À≈ = (D - 25.4) x 100% 25.4 D = √–¬–‡ âπºà“π»πŸ ¬°å ≈“ß∑’Ë·ºÕà Õ° (§“à ‡©≈¬’Ë ) ‡ªìπ‡´π쇑 ¡μ√ 4. °“√√“¬ß“π §à“√âÕ¬≈–¢Õß°“√‰À≈„Àâ„™â∑»π‘¬¡ 1 μ”·Àπàß ∫—π∑÷°„π·∫∫øÕ√å¡ ‡≈¢∑’Ë ∫ø. ¡∂.(∑) 103.2-2550 : «∏‘ ’°“√∑¥ Õ∫§à“°“√¬∫ÿ μ«— ¢ÕߧÕπ°√’μ ‚¥¬„™‚â μ–ä °“√‰À≈ 5. ‡°≥±å°“√μ¥—  π‘ ·≈–§«“¡§≈“¥‡§≈ÕË◊ π∑’¬Ë Õ¡„Àâ 5.1 §“à √âÕ¬≈–¢Õß°“√‰À≈ μÕâ ß¡§’ à“Õ¬àŸ√–À«à“ß√Õâ ¬≈– 50 ∂÷ß√Õâ ¬≈– 100 6. ¢âÕ§«√√–«—ß 6.1 °Õà π°“√∑¥ Õ∫μÕâ ߇™Á¥‚μä–∑¥ Õ∫„Àâ –Õ“¥ ª√“»®“°§Õπ°√μ’ ∑’μË °Õ¬àŸπÕ°·∫∫À≈àÕ 6.2 ∑”°“√À¡πÿ ¡◊ÕÀ¡πÿ ‡æ◊ËÕ¬°‚μ–ä °“√‰À≈ „À°â √–∑∫¥â«¬Õ—μ√“§«“¡‡√«Á  ¡”Ë ‡ ¡Õ 6.3 „π¢≥–∑”°“√∑¥ Õ∫¡«≈√«¡®–μÕâ ߉¡à‡°¥‘ °“√·¬°μ«— 7. Àπß—  ◊ÕÕâ“ßÕ‘ß 7.1 AMERICAN SOCIETY OF TESTING AND MATERIALS ; ASTM STANDARD : C 124-71 7.2 §Õπ°√μ’ ‡∑§‚π‚≈¬’ ¢Õß °“√≥ÿ “ „®ªí≠≠“  ∂“∫π— ‡∑§‚π‚≈¬æ’ √–®Õ¡‡°≈â“æ√–π§√‡Àπ◊Õ À¡«¥ß“π‚§√ß √â“ß·≈–ª∞æ«’ ‘»«°√√¡ 1-45

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ ‚§√‚ߧ°√“ß√°Ç“√Ç...Ç.....Ç....Ç.....Ç.....Ç....Ç.....Ç....Ç.....Ç....Ç.....Ç....Ç.....Ç..... ∫∫øø.. ¡¡∑∂∂.(.(∑∑)) 110033.2.2--22555500 ∑–‡∫¬’ π ÇÇ....Ç.....Ç....Ç.....Ç....Ç.....Ç....Ç.....Ç....Ç.....Ç....Ç.....Ç.....Ç....Ç.....Ç....Ç.....Ç..  ∂“ π∂∑“’Ë°πàÕ∑ Ë°’ √Õà â“ ß√Çâ“ßÇ...Ç....Ç.....Ç.....Ç....Ç.....Ç....Ç.....Ç....Ç.....Ç....Ç.. (Àπ૬ߓπ∑∑’Ë Ì“°“√∑¥ Õ∫) ∑–‡∫¬’ π∑¥ Õ∫................................ ÇÇ....Ç.....Ç....Ç.....Ç....Ç.....Ç....Ç.....Ç....Ç.....Ç....Ç.....Ç.....Ç....Ç.....Ç....Ç.....Ç.. °“√∑¥ Õ∫§à“°“√¬ÿ∫μ—«¢ÕߧÕπ°√’μ ºŸâ√—∫º®√⟠â“∫— ß®À“â √ß◊ÕÀº√Ÿâπ◊ÕÌ“º ŸâπàߔǠÇàß...Ç....Ç.....Ç....Ç.....Ç....Ç.....Ç....Ç........ ∑¥ Õ∫ÇÇÇÇÇÇ ™π™‘¥πμ—«¥‘ Õμ¬—«à“Õ߬Ǔà ßÇ...Ç.....Ç....∑Ç¥. ∑Õ¥∫ §Õ∫√ßÈ—§∑√.’Ë—Èß..∑...’ËÇ....Ç.....Ç... ‚¥¬„™â‚μä–°“√‰À≈ º∑⟠¥ Õ∫ ∑¥∑ Õ¥∫ «Õ—π∫∑«’ËÇπ— ∑Ç.Ë’ ..Ç.....Ç....Ç.....Ç..·Çºàπ.·∑º’Ë..àπ...∑..’ËÇ.....Ç.....Ç....Ç.... (FL(FOloWw TTAabBlLeE) ) ºμ⟠√«® Õ∫ Õπ¡ÿ —μ‘ √–¬–‡ πâ ºà“π»πŸ ¬°å ≈“ß∑Ë·’ ºàÕÕ° (D) ÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇ. ‡´π쑇¡μ√ √âÕ¬≈–¢Õß°“√‰À≈ = (D › 25.4) x 100% √Õâ ¬≈–¢Õß°“√‰À≈ 25.4 = ÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇ À¡“¬‡Àμÿ : 1-46 À¡«¥ß“π‚§√ß √“â ß·≈–ª∞æ’«‘»«°√√¡

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ ¡∂.(∑) 104-2550 ¡“μ√∞“π°“√∑¥ Õ∫À“§“à πÈ”∑„Ë’ ™â„πß“π§Õπ°√’μ 1. ¢Õ∫¢“à ¬ ¡“μ√∞“π°“√∑¥ Õ∫π’È §√Õ∫§≈ÿ¡∂÷ß°“√∑¥ Õ∫§ÿ≥ ¡∫—μ‘∑“ß°“¬¿“æ·≈–∑“߇§¡’¢Õß πÈ”∑’Ë„™â„π°“√º ¡∑”§Õπ°√’μ·≈–„™â„π°“√∫ࡧÕπ°√’μ ‚¥¬°”Àπ¥§ÿ≥≈—°…≥–∑Ë’μâÕß°“√ «‘∏’ °“√«‘‡§√“–Àå·≈–°“√‡°∫Á μ«— Õ¬“à ß 2. 𑬓¡ 2.1 πÈ”∑Ë’„™„â πß“π§Õπ°√μ’ À¡“¬∂ß÷ πÈ”∑Ë’π”¡“„™â„π°“√º ¡‡æ◊ËÕ∑”§Õπ°√μ’ ·≈–/À√◊Õπ”¡“„™â „π°“√∫ࡧÕπ°√’μ 2.2 Àπ૬ ‡ÕπÁ ∑¬’ Ÿ (NTU, Nephelometric Turbidity Unit) À¡“¬∂÷ß Àπ૬«—¥§“à §«“¡¢ÿπà „ππ”È 2.3 §“à pH À¡“¬∂ß÷ §“à ∑·Ë’  ¥ß∂÷ߧ«“¡‡ªπì °√¥-¥“à ߢÕßπ”È 2.4 Àπ«à ¬ ppm À¡“¬∂÷ß Àπ÷Ëß à«π„π≈“â π à«π (Parts-Per-Million) 3. «∏‘ ’∑” 3.1 ‡§√Õ◊Ë ß¡◊Õ ·≈–Õÿª°√≥å 3.2 °“√‡°∫Á μ—«Õ¬“à ß ‡æ◊ËÕ„À≥âμ«— ·∑π¢ÕßπÈ”∑μË’ âÕß°“√∑√“∫§ÿ≥≈—°…≥–∑“ß°“¬¿“æ·≈–∑“߇§¡’ °“√‡°Á∫μ—«Õ¬à“ßπÈ”„Àâ∑”°“√‡°Á∫¥â«¬¿“™π–∫√√®ÿ ‚¥¬„™â¢«¥·°â«À√◊Õ¢«¥æ≈“ μ‘° ¡’§«“¡ ®ÿ‰¡àπâÕ¬°«à“ 2,500 ≈Ÿ°∫“»°å‡´π쑇¡μ√ ∑Ë’ –Õ“¥·≈–·Àâß °àÕπ∑”°“√‡°Á∫μ—«Õ¬à“ßπÈ”„Àâ„™â πÈ”∑’Ë®–‡°Á∫≈â“ߢ«¥Õ’°§√È—ßÀπË÷ß Àâ“¡π”¿“™π–∑’ˇ§¬∫√√®ÿ¬“ “√‡§¡’ πÈ”¡—π À√◊Õ Ë‘ßÕ◊Ëπ∑’ˉ¡à  “¡“√∂≈â“ßÕÕ°‰¥âÀ¡¥¡“„™â„π°“√‡°Á∫μ—«Õ¬à“ßπÈ” «‘∏’°“√‡°Á∫μ—«Õ¬à“ßπÈ”®“°·À≈àßμà“ßÊ  “¡“√∂°√–∑”‰¥â ¥ß— π’È §◊Õ 3.2.1 πÈ”∫“¥“≈ °Õà π∑”°“√‡°∫Á μ«— Õ¬à“ßπÈ”®“°∫àÕ∫“¥“≈ §«√ ∫Ÿ πÈ”∑ß‘È ª√–¡“≥ 5 π“∑’ ·≈â«®÷ß∑”°“√‡°Á∫μ—«Õ¬à“ßπÈ” ∂Ⓡ°Á∫®“°°äÕ°πÈ”¢Õß∫àÕ∫“¥“≈μâÕß≈â“ß°äÕ°„Àâ –Õ“¥ ‡ ’¬°àÕπ ·≈â«®÷߇ªî¥πÈ”∑‘È߉«â —° 2-3 π“∑’ ‡æ◊ËÕ„ÀâπÈ”∑’˧â“ßÕ¬Ÿà„π∑àÕ‰À≈ÕÕ°„ÀâÀ¡¥°àÕπ °“√‡°Á∫μ—«Õ¬à“ßπÈ” ∫√√®ÿ≈ß„π¢«¥§«√‡ªìπ‡«≈“∑Ë’πÈ”‰À≈Õ¬à“ß ¡Ë”‡ ¡Õ √–«—ßÕ¬à“„Àâ  Ë‘ß‡®◊ÕªπÕË◊πμ°≈߉ª„π¢«¥ ·≈⫪î¥Ω“®ÿ°„Àâ·πàπ ªî¥©≈“°·®âß√“¬≈–‡Õ’¬¥„π°“√‡°Á∫ §◊Õ  ∂“π∑Ë’‡°Á∫‡«≈“·≈–™Ë◊ÕºŸâ‡°Á∫μ—«Õ¬à“ßπÈ” „Àâ∑”°“√‡°Á∫μ—«Õ¬à“ß Õ¬à“ßπâÕ¬ 2,500 ≈°Ÿ ∫“»°‡å ´π쑇¡μ√ ‡æÕË◊ ‡ªπì μ«— ·∑π¢Õß·À≈àßπ”È πÈπ— Ê À¡«¥ß“π‚§√ß √â“ß·≈–ª∞æ«’ ‘»«°√√¡ 1-47

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ 3.2.2 π”È º‘«¥‘π °“√‡°∫Á π”È μ«— Õ¬à“ß®“°Õà“߇°Á∫πÈ” ≈”§≈Õß ·¡πà ”È À√◊Õ·À≈àßπ”È ∏√√¡™“μ‘ ÕË◊πÊ „Àâ∑”°“√‡°Á∫‚¥¬À¬àÕπ¢«¥‡°Á∫πÈ”μ—«Õ¬à“ß ∑’Ë∑”§«“¡ –Õ“¥·≈â«≈߉ª„π·À≈àß πÈ” ·≈â«√Õ —°§√Ÿà ‡æË◊Õ„Àâ ¿“æπÈ”∑’ˇ°‘¥°“√‡ª≈Ë’¬π·ª≈ß ®“°°“√À¬àÕπ¢«¥‡°Á∫πÈ” °≈—∫ àŸ ¿“懥‘¡°àÕπ ·≈â«®÷߇ªî¥®ÿ°¢«¥„ÀâπÈ”‰À≈‡¢â“¢«¥ ªî¥®ÿ°„Àâ·πàπ ªî¥©≈“°·®âß √“¬≈–‡Õ’¬¥„π°“√‡°Á∫ À“°‡ªìπ·À≈àßπÈ”„À≠à „Àâ∑”°“√‡°Á∫μ—«Õ¬à“ßÕ¬à“ßπâÕ¬ 5 μ—«Õ¬à“ß ‡æ◊ËÕ‡ªìπμ—«·∑π ¢Õß·À≈àßπÈ”πÈ—πÊ ·μà≈–®ÿ¥∑’Ë∑”°“√‡°Á∫μ—«Õ¬à“ß„Àâ¡’ª√‘¡“≥ ‰¡àμË”°«à“ 1,000 ≈Ÿ°∫“»°å‡´π쑇¡μ√ ‡æË◊Õ∑Ë’®–‰¥â¡’ª√‘¡“≥‡æ’¬ßæÕ∑Ë’„™â„π°“√«‘‡§√“–Àå ‰¥ºâ ≈‡À¡Õ◊ π„π π“¡®√ß‘ 3.2.3 πÈ”ª√–ª“ „À∑â ”°“√‡°Á∫μ«— Õ¬“à ßπÈ”ª√–ª“®“°°äÕ° ‚¥¬„™«â ‘∏‡’ ¥’¬«°π— °∫— °“√‡°∫Á πÈ”∫“¥“≈®“°°Õä ° 3.3 ·∫∫øÕ√¡å „™â·∫∫øÕ√å¡ ∫ø. ¡∂.(∑) 104-2550 : °“√∑¥ Õ∫πÈ”∑„Ë’ ™â„πß“π§Õπ°√μ’ 3.4 °“√∑¥ Õ∫ 3.4.1 °“√∑¥ Õ∫§ÿ≥ ¡∫—μ‘¢ÕßπÈ”∑“ß°“¬¿“æ ‚¥¬∑”°“√∑¥ Õ∫„π‡√◊ÕË ß§«“¡¢πàÿ ·≈– §«“¡‡ªìπ°√¥-¥à“ß «‘∏’°“√∑¥ Õ∫∑”μ“¡¡“μ√∞“πº≈‘μ¿—≥±åÕÿμ “À°√√¡ ¡Õ°. 257 : π”È ∫√‚‘ ¿§ 3.4.2 °“√∑¥ Õ∫§≥ÿ  ¡∫μ— ‘¢ÕßπÈ”∑“߇§¡’ ∑”°“√«‡‘ §√“–ÀåÀ“ª√‘¡“≥¢Õß´≈— ‡øμ (SO ) 4 ·≈–§≈Õ‰√¥å (Cl) ¢ÕßπÈ”∑Ë’®–π”¡“„™â„πß“π§Õπ°√’μ ‚¥¬„Àâ∑”μ“¡«‘∏’°“√∑¥ Õ∫ ¡“μ√∞“πº≈‘μ¿—≥±åÕμÿ  “À°√√¡ ¡Õ°. 257 : π”È ∫√‘‚¿§ 3.4.3 ∑”°“√∑¥ Õ∫‡ª√’¬∫‡∑’¬∫ (Comparative Test) „π‡√ÕË◊ ß°“√∑¥ Õ∫À“√–¬–‡«≈“°“√ °àÕμ—«¢ÕߪŸπ´’‡¡πμå (Setting Time) ·≈–°“√∑¥ Õ∫À“§«“¡μâ“π·√ßÕ—¥ (Compressive Strength) ¢Õß°âÕπ≈Ÿ°∫“»°å¡Õ√åμâ“μ“¡«‘∏’¡“μ√∞“π ¡∂.(∑) 105.1 : ¡“μ√∞“π°“√∑¥ Õ∫§«“¡μâ“π·√ßÕ—¥¢Õß·∑àߧÕπ°√’μ ‚¥¬∑”°“√‡ª√’¬∫‡∑’¬∫ √–À«à“ßπÈ”μ—«Õ¬à“ß∑’Ë®–π”¡“„™â„πß“π§Õπ°√’μ°—∫πÈ”°≈—Ëπ ∑’Ë®–„™âªŸπ´’‡¡πμå„π°“√ ∑¥ Õ∫™π¥‘ ‡¥¬’ «°—π 4. °“√√“¬ß“πº≈ „Àâ√“¬ß“πº≈°“√∑¥ Õ∫„π ∫ø. ¡∂.(∑) 104-2550 : °“√∑¥ Õ∫πÈ”∑Ë’„™â„πß“π§Õπ°√’μ ‚¥¬„™â√“¬ß“πº≈°“√∑¥ Õ∫‡√Ë◊Õߧ«“¡¢àÿ𠧫“¡‡ªìπ°√¥-¥à“ß ª√‘¡“≥¢Õß´—≈‡øμ ·≈–§≈Õ- ‰√¥å ”À√—∫√–¬–‡«≈“°“√°àÕμ—«¢ÕߪŸπ´’‡¡πμå ·≈–§«“¡μâ“π·√ßÕ—¥¢Õß°âÕπ≈Ÿ°∫“»°å¡Õ√åμâ“ „À¡â ’√“¬≈–‡Õ¬’ ¥∂ß÷ ∑»π¬‘ ¡ 2 μ”·Àπßà 1-48 À¡«¥ß“π‚§√ß √“â ß·≈–ª∞æ«’ »‘ «°√√¡

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ 5. ‡°≥±μå —¥ π‘ ·≈–§«“¡§≈“¥‡§≈ËÕ◊ π∑ˬ’ Õ¡„Àâ 5.1 π”È ∑„Ë’ ™„â πß“π§Õπ°√μ’ ®–μâÕß¡’‡°≥±°å ”Àπ¥§≥ÿ  ¡∫μ— ∑‘ ’ËμâÕß°“√∑“ß°“¬¿“æ ¥ß— π’È §Õ◊ ¡’ §«“¡¢ÿàπ (Turbidity) ‰¡à‡°‘π 2,000 Àπ૬‡ÕÁπ∑’¬Ÿ (NTU) ·≈–®–μâÕß¡’§«“¡‡ªìπ°√¥-¥à“ß Õ¬àŸ‰¥™â à«ß√–À«“à ß pH 6.5-8.5 5.2 πÈ”∑Ë’„™„â πß“π§Õπ°√’μ ®–μÕâ ß¡‡’ °≥±°å ”Àπ¥§ÿ≥ ¡∫μ— ‘∑“߇§¡’ ∑μË’ âÕß°“√ ¥ß— π’È §◊Õ μâÕß¡’ª√‘¡“≥´—≈‡øμ„ππÈ”‰¡à‡°π‘ 10,000 ppm. ·≈–®–μâÕß¡’ª√¡‘ “≥¢Õߧ≈Õ‰√¥å„ππ”È ‰¡à‡°π‘ 20,000 ppm. 5.3 °“√∑”°“√∑¥ Õ∫‡ª√¬’ ∫‡∑’¬∫ √–À«“à ßπÈ”μ«— Õ¬à“ß·≈–π”È °≈πË— ®–μÕâ ß„Àºâ ≈°“√∑¥ Õ∫À“ √–¬–°“√°àÕμ—«√–¬–μâπ¢ÕߪŸπ´’‡¡πμå ·μ°μà“ß°—π‰¡à‡°‘π 10 π“∑’ ·≈–º≈°“√∑¥ Õ∫À“°”≈—ß √∫— ·√ßÕ—¥¢Õß°âÕπ≈Ÿ°∫“»°¡å Õ√μå â“ ®–μÕâ ß„Àâ§à“°”≈ß— √∫— ·√ßÕ—¥μË”≈߉¥â‰¡‡à °π‘ √âÕ¬≈– 10 6. ¢âÕ§«√√–«ß— 6.1 À“°∑”§«“¡ –Õ“¥¢«¥¥â«¬ºß´—°øÕ° ®–μÕâ ß≈â“ß®π·π„à ®‡ ¬’ °Õà π«“à ≈“â ßÕÕ°®πÀ¡¥®√ß‘ Ê 6.2 ‡¡Õ◊Ë ‡°∫Á μ«— Õ¬à“ßπ”È ‡√’¬∫√Õâ ¬·≈«â „À√â ’∫π” àßÀÕâ ߪØ∫‘ μ— °‘ “√ ‡æ◊ÕË ∑”°“√«‘‡§√“–Àå‡√«Á ∑’Ë ÿ¥‡∑“à ∑Ë’®–∑”‰¥â ·≈–‰¡à§«√„À⢫¥πÈ”μ«— Õ¬à“ß∂Ÿ°· ß·¥¥ 7. Àπ—ß ◊ÕÕ“â ßÕ‘ß 7.1 THE AMERICAN ASSOCIATION OF STATE HIGHWAY AND TRANSPORTATION OFFICIALS ; AASHTO : T 26-72 7.2 AMERICAN SOCIETY FOR TESTING AND MATERIALS ; ASTM DESIGNATION : D 1252-60, D 516-63T 7.3 PORTLAND CEMENT ASSOC. (1968) çDESIGN. AND CONTROL OF CONCRETE MIXTUREé PCA, SKOKI, 1968 7.4 ¡“μ√∞“πº≈μ‘ ¿—≥±Õå μÿ  “À°√√¡ ¡Õ°. 257-2529 : πÈ”∫√‚‘ ¿§ À¡«¥ß“π‚§√ß √“â ß·≈–ª∞æ«’ »‘ «°√√¡ 1-49

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°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ ¡∂.(∑) 105.1-2550 ¡“μ√∞“π°“√∑¥ Õ∫À“§“à §«“¡μ“â π·√ßÕ—¥¢Õß·∑àߧÕπ°√μ’ (Compressive Strength of Concrete) 1. ¢Õ∫¢“à ¬ ¡“μ√∞“π°“√∑¥ Õ∫π’È §√Õ∫§≈ÿ¡∂÷ß°“√À“§à“§«“¡μâ“π·√ßÕ—¥¢Õß·∑àߧÕπ°√’μ√Ÿª∑√ß °√–∫Õ° ·≈–√Ÿª≈°Ÿ ∫“»°å ´Ë÷ß®–‰¥â®“°°“√À≈Õà „π·∫∫À≈Õà À√◊Õ®“°°“√‡®“–¡“∑¥ Õ∫°‰Á ¥â 2. «∏‘ ∑’ ” 2.1 ‡§√ÕË◊ ß¡Õ◊ 2.1.1 ‡§√Ë◊Õß°¥∑¥ Õ∫ ‡§√Õ◊Ë ß°¥‡ªπì ·∫∫„¥°Á‰¥â ∑Ë∑’ ”„Àâπ”È Àπ—°°¥‰¥â Ÿß‡æ’¬ßæÕÕ¬àŸ„π™à«ß „™âß“π‰¥â ·≈–¬Õ¡„À⺑¥æ≈“¥‰¥â‰¡à‡°‘π√âÕ¬≈– 1 ‡§√Ë◊Õß°¥®–μâÕß “¡“√∂‡æË‘¡·√ß°¥ ‰¥âÕ¬à“ß ¡Ë”‡ ¡Õ·≈–‰¡à°√–μÿ° ‡§√◊ËÕß∑¥ Õ∫·∫∫À¡ÿπ‡°≈’¬« (Screw-Type) ®–μâÕß ‡ªìπ‡§√◊ËÕß∑Ë’À—«°¥ “¡“√∂‡§≈◊ËÕπ∑Ë’¥â«¬§«“¡‡√Á«ª√–¡“≥ 1.3 ¡‘≈≈‘‡¡μ√μàÕπ“∑’  ”À√—∫‡§√◊ËÕß∑¥ Õ∫·∫∫‰Œ¥√Õ≈‘° μâÕ߇ªìπ‡§√Ë◊Õß∑Ë’ “¡“√∂„ÀâπÈ”Àπ—°¥â«¬Õ—μ√“ §ß∑’Ë Õ¬„àŸ π™«à ß 1.43 ∂ß÷ 3.47 °‚‘ ≈°√—¡μàÕμ“√“߇´π쇑 ¡μ√μÕà «π‘ “∑’  à«π∑Ë’„™â°¥¢Õ߇§√◊ËÕß∑¥ Õ∫ ®–μâÕߪ√–°Õ∫¥â«¬·ºàπ‡À≈Á°∑¥ Õ∫ (Steel Bearing Plate) 2 ·ºàπ ¢π“¥„À≠à°«à“¢π“¥¢Õß·∑àπ∑¥ Õ∫‰¡àπâÕ¬°«à“ 10 ¡‘≈≈‘‡¡μ√ ·ºàπ‡À≈Á°μ—«∫π¡’≈—°…≥–‡ªìπ·ªÑπ°¥∞“π§√Ë÷ß∑√ß°≈¡ (Spherically Seated Block) ·¢«π¬÷¥‰«â°—∫‡§√Ë◊Õ߇æË◊Õ„À⢬—∫μ—«‰¥â  à«π·ºàπ‡À≈Á°μ—«≈à“ß ®–μâÕ߬÷¥μ‘¥°—∫ à«π≈à“ß ¢Õ߇§√◊ËÕß ·≈–μâÕß¡’§«“¡Àπ“Õ¬à“ßπâÕ¬ 50 ¡‘≈≈‘‡¡μ√ º‘« —¡º— ¢Õß·ºàπ‡À≈Á°∑—Èß  Õß ®–μâÕ߇√’¬∫¡’§«“¡‡√’¬∫§≈“¥‡§≈◊ËÕπ‰¥â‰¡à‡°‘π 0.025 ¡‘≈≈‘‡¡μ√ „π√–¬–∑“ß 150 ¡‘≈≈‘‡¡μ√ °“√‡æË‘¡·√ß°¥μâÕß∑”‰¥âÕ¬à“ßμàÕ‡πË◊Õß ‰¡à¡’®—ßÀ«–À¬ÿ¥À√◊Õ°√–μÿ°„π √–À«“à ß°“√‡æ¡‘Ë ·√ß°¥ 2.1.2 ‡«Õ√‡å π’¬√§å “≈‘‡ªÕ√å ¡§’ «“¡≈–‡Õ¬’ ¥∂ß÷ 0.1 ¡≈‘ ≈‡‘ ¡μ√ 2.1.3 ‡§√Ë◊Õß™Ëß— πÈ”Àπ—° ´Ëß÷ ¡’§«“¡≈–‡Õ’¬¥∂÷ß 1 °√¡— 2.1.4 ‡§√◊ËÕß¡Õ◊ ‡§≈◊Õ∫º«‘ Àπâ“¢Õß·∑ßà §Õπ°√’μ √ªŸ ∑√ß°√–∫Õ° 2.2 ·∫∫øÕ√å¡ „À∫â —π∑÷°„π·∫∫øÕ√å¡ ∫ø. ¡∂.(∑) 105.1-2550 : °“√∑¥ Õ∫§«“¡μ“â π·√ßÕ¥— ¢Õß·∑ßà §Õπ°√μ’ À¡«¥ß“π‚§√ß √“â ß·≈–ª∞æ’«‘»«°√√¡ 1-51

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ 2.3 °“√‡μ√¬’ ¡μ«— Õ¬“à ß 2.3.1 ·∑ßà ∑¥ Õ∫´Ë÷߉¥â®“°°“√À≈àÕ®–μâÕ߇ªìπ√Ÿª∑√ß°√–∫Õ° ¢π“¥‡ πâ º“à π»πŸ ¬å°≈“ß 150+0.75 ¡‘≈≈‘‡¡μ√ ·≈– Ÿß 300+3 ¡‘≈≈‘‡¡μ√ À√◊Õ‡ªìπ√Ÿª≈Ÿ°∫“»°å ¢π“¥ 150+0.75 ¡‘≈≈‘‡¡μ√ ‚¥¬∑”°“√‡°Á∫μ—«Õ¬à“ßμ“¡ ¡∂.(∑) 102 : ¡“μ√∞“π°“√‡°Á∫μ—«Õ¬à“ß §Õπ°√’μ„πÀπâ“ß“π·≈–°“√𔉪∫”√ÿß√—°…“ 2.3.2 °“√‡§≈Õ◊ ∫º‘«Àπâ“ (Capping) ·∑àß∑¥ Õ∫√Ÿª∑√ß°√–∫Õ° «— ¥∑ÿ ’Ë„™â„π°“√‡§≈Õ◊ ∫ º‘«Àπâ“√—∫·√ßÕ—¥¢Õß·∑àßμ—«Õ¬à“ß (Capping Compound) μâÕß “¡“√∂√—∫·√ßÕ—¥‰¥â Ÿß °«à“·√ßÕ—¥¢Õß·∑àߧÕπ°√’μ∑¥ Õ∫ °“√‡§≈◊Õ∫ª≈“¬∑—Èß ÕߢÕß·∑àß∑¥ Õ∫ μâÕß ‡§≈◊Õ∫„ÀâμÈ—ß©“°°—∫·°π¢Õß·∑àß∑¥ Õ∫ §«“¡‡√’¬∫¢Õߺ‘«Àπâ“∑¥ Õ∫∑Ë’‰¥â√—∫°“√ ‡§≈◊Õ∫·≈«â ¬Õ¡„À§â ≈“¥‡§≈ÕË◊ π‰¥â‰¡‡à °‘π 0.1 ¡‘≈≈‡‘ ¡μ√ 2.3.3 ·∑ßà ∑¥ Õ∫∑’‰Ë ¥®â “°°“√‡®“– ®–μÕâ ߇ªìπ√Ÿª°√–∫Õ°‡ πâ º“à π»πŸ ¬°å ≈“߉¡πà Õâ ¬°«“à 2 ‡∑à“ ¢Õß¢π“¥„À≠à∑’Ë ÿ¥¢Õß¡«≈À¬“∫ ·≈–μâÕ߉¡àπâÕ¬°«à“ 100 ¡‘≈≈‘‡¡μ√ §«“¡¬“« ‡¡ÕË◊ ¬—߉¡‡à §≈◊Õ∫ª≈“¬μÕâ ߉¡àπâÕ¬°«“à √Õâ ¬≈– 95 ¢Õ߇ âπºà“π»πŸ ¬å°≈“ß °àÕπ°“√‡§≈◊Õ∫º‘«·∑àߧÕπ°√’μ∑’ˉ¥â®“°°“√‡®“– ®–μâÕß¡’§«“¡§≈“¥‡§≈◊ËÕπ ¢Õߧ«“¡‡√’¬∫∑Ë’º‘«Àπâ“μ—¥‰¡à‡°‘π 5 ¡‘≈≈‘‡¡μ√ ¢Õß¡ÿ¡∑’ËÀπâ“μ—¥∑”°—∫·°πμ“¡¬“« ®“°¡ÿ¡©“°‰¡à‡°‘π 5 Õß»“ ·≈–‡ âπºà“π»Ÿπ¬å°≈“ß ∑’ËÀπâ“μ—¥∑—Èß Õß®“°‡ âπºà“π »πŸ ¬°å ≈“߇©≈’¬Ë ‰¡‡à °‘π 2.5 ¡‘≈≈‘‡¡μ√ §«“¡‡√’¬∫¢Õߺ‘«Àπâ“ ·∑àß∑¥ Õ∫∑’ˉ¥â®“°°“√‡®“– ‡¡Ë◊Õ‰¥â√—∫°“√‡§≈◊Õ∫·≈â« ¬Õ¡„Àâ§≈“¥‡§≈Ë◊Õπ‰¥â‰¡à‡°‘π 0.1 ¡‘≈≈‘‡¡μ√ ·∑àß∑¥ Õ∫ ´Ë÷߉¥â®“°°“√‡®“–„À⇮“–‡¡Ë◊Õ §Õπ°√’μ¡’Õ“¬ÿ‰¡àμË”°«à“ 14 «—π ·≈–μâÕßÕ¬Ÿà„π ¿“æ∑’Ë¥’‰¡à¡’√Õ¬√â“« √Õ¬∫Ë‘πÀ√◊Õ‡ªìπ ‚æ√ß 2.3.4 ∑”°“√«—¥¢π“¥·≈–™ß—Ë πÈ”Àπ°— ·∑ßà ∑¥ Õ∫ ‚¥¬„À«â ¥— À“‡ πâ º“à π»Ÿπ¬°å ≈“ß À√◊Õ¢π“¥ Àπâ“μ—¥·∑àß ’ˇÀ≈Ë’¬¡®—μÿ√— ‡ªìπ‡´π쑇¡μ√ ∑»π‘¬¡ 2 μ”·Àπàß ‚¥¬‡©≈’ˬ§à“‡ âπºà“π »Ÿπ¬å°≈“ß 2 §à“ ∑’Ë«—¥‰¥âÀ√◊Õ«—¥¢π“¥ Ë’‡À≈’ˬ¡Àπâ“μ—¥∑’˺à“π»Ÿπ¬å°≈“߇©≈Ë’¬ À√◊Õ¢π“¥ ∑Ë’«—¥‰¥âπÈ’®–„™â‡ªìπ§à“ ”À√—∫§”π«≥À“æ◊Èπ∑Ë’Àπâ“μ—¥¢Õß·∑àß∑¥ Õ∫ „π°“√«—¥§«“¡ Ÿß „Àâ«—¥§«“¡ Ÿß¢Õß·∑àß∑¥ Õ∫ √«¡∑ȗߧ«“¡Àπ“¢Õß«— ¥ÿ‡§≈◊Õ∫º‘«Àπâ“Àπ૬‡ªìπ ‡´π쑇¡μ√ ∑»π‘¬¡ 2 μ”·Àπàß °“√™—ËßπÈ”Àπ—°·∑àß∑¥ Õ∫ ‡æ◊ËÕÀ“§«“¡Àπ“·πàπ¢Õß ·∑ßà §Õπ°√’μ „À™â Ëß— π”È Àπ—°·∑àß∑¥ Õ∫‡ªπì °‚‘ ≈°√—¡ ∑»π¬‘ ¡ 2 μ”·Àπàß 2.3.5 °“√«¥— ¢π“¥¢Õß·∑àß∑¥ Õ∫ ´ß÷Ë ‰¥â®“°°“√‡®“– μÕâ ß«¥— „À≥≈â –‡Õ’¬¥∂÷ß 1 ¡‘≈≈‡‘ ¡μ√ ¿“¬À≈—ß°“√‡§≈◊Õ∫º‘«Àπâ“¢Õß·∑àß∑¥ Õ∫„Àâ‡√’¬∫°“√«—¥‡ âπºà“π»Ÿπ¬å°≈“ß „Àâ«—¥ 3 μ”·Àπàß §◊Õ ª≈“¬∑—Èß Õߢâ“ß ·≈–∑’Ë°Ë÷ß°≈“ß·∑àß∑¥ Õ∫ ‚¥¬«—¥μ”·Àπàß≈– 2 ·π« ¢Õ߇ âπºà“π»Ÿπ¬å°≈“ß∑Ë’μ—Èß©“°°—∫§à“∑Ë’«—¥‰¥â∑È—ß 6 §à“ π”¡“‡©≈’ˬ‡ªìπ§à“∑’Ë„™â„π°“√ 1-52 À¡«¥ß“π‚§√ß √â“ß·≈–ª∞æ«’ »‘ «°√√¡

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ §”π«≥ °“√«—¥§«“¡¬“« „Àâ«—¥ 4 μ”·Àπàß §◊Õ ∑’˺‘«μ“¡¬“«¢Õß·∑àß∑¥ Õ∫ ‚¥¬¡’ √–¬–Àà“ßμ“¡‡ âπ√Õ∫√Ÿª¢Õß¿“§μ—¥¢«“ß∑Ë’ª≈“¬‡∑à“°—π ·≈â«À“§à“‡©≈Ë’¬ ”À√—∫𔉪 „™„â π°“√§”π«≥ 2.4 °“√∑¥ Õ∫ 2.4.1 °“√«“ß·∑àß∑¥ Õ∫∫π‡§√Õ◊Ë ß°¥μâÕ߇ªìπ‰ªμ“¡πÈ’ - º«‘ ·ºπà ‡À≈Á°¥â“π ¡— º — °∫— ·∑àß∑¥ Õ∫μâÕß –Õ“¥ª√“»®“°πÈ”¡—π - ®—¥·π«»πŸ ¬å°≈“ߢÕß·ºπà ‡À≈°Á μÈß— μ«— ∫π·≈–μ—«≈“à ß„ÀâÕ¬àŸ„π·π«‡¥’¬«°—π - °“√«“ß·∑àß∑¥ Õ∫μâÕß„Àâ·π«·°π¢Õß·∑àß∑¥ Õ∫∑—∫°—∫·π«»Ÿπ¬å°≈“ߢÕ߇§√◊ËÕß °¥∑¥ Õ∫ - º‘«·ºπà ‡À≈Á°μÕâ ß ¡— º— °∫— ·∑ßà ∑¥ Õ∫·π∫ π‘∑ 2.4.2 ‡¡◊ËÕ«“ß·∑ßà ∑¥ Õ∫∫π‡§√Ë◊Õß°¥∑¥ Õ∫ ·≈–®¥— „À·â ºàπ‡À≈°Á  ¡— º — °—∫·∑ßà ∑¥ Õ∫ ·π∫ π‘∑¥’·≈â« ®÷߇√Ë‘¡„ÀâπÈ”Àπ—°°¥Õ¬à“ß ¡Ë”‡ ¡Õ ‚¥¬¡’Õ—μ√“§ß∑Ë’Õ¬àŸ„π™à«ß 1.43 ∂÷ß 3.47 °‘‚≈°√—¡μàÕμ“√“߇´π쑇¡μ√μàÕ«‘π“∑’ „π™à«ß§√Ë÷ß·√°¢ÕßπÈ”Àπ—°°¥ Ÿß ÿ¥∑’Ë·∑àß ∑¥ Õ∫®–√—∫‰¥âπ—Èπ ¬Õ¡„Àâ„™âÕ—μ√“°“√°¥ Ÿß°«à“°”Àπ¥‰¥â ·≈–Àâ“¡ª√—∫Õ—μ√“°“√°¥ À√◊Õ à«π„¥Ê ¢Õ߇§√Ë◊Õß∑¥ Õ∫„π¢≥–∑Ë’·∑àß∑¥ Õ∫Õ¬àŸ„π™à«ß®ÿ¥§≈“° (Yield Point) ·≈–®ÿ¥«‘∫—μ‘ (Failure) 2.4.3 „À∑â ”°“√°¥®π°√–∑Ëß— ·∑ßà ∑¥ Õ∫∂÷ß®¥ÿ «‘∫—μ‘ ∫—π∑÷°§“à π”È Àπ—°°¥ Ÿß ÿ¥∑·’Ë ∑àß∑¥ Õ∫  “¡“√∂√—∫‰¥â ·≈–„Àâ∫—π∑÷°√Ÿª≈—°…≥–°“√·μ°¢Õß·∑àß∑¥ Õ∫π—Èπ„π·∫∫øÕ√å¡ ∑Ë’ ∫ø. ¡∂.(∑) 105.1-2550 : °“√∑¥ Õ∫§«“¡μ“â π·√ßÕ—¥¢Õß·∑àߧÕπ°√μ’ 3. °“√§”π«≥ 3.1 °“√§”π«≥ §à“§«“¡μ“â π·√ßÕ¥— ¢Õß·∑àß∑¥ Õ∫„Àâ≈–‡Õ’¬¥ ∂÷ß∑»π‘¬¡ 2 μ”·Àπßà ‰¥®â “°  Ÿμ√ §«“¡μ“â π·√ßÕ¥— ¢Õß·∑àß∑¥ Õ∫ = π”È Àπ—°°¥ Ÿß ÿ¥∑’·Ë ∑ßà ∑¥ Õ∫√∫— ‰¥â (°‚‘ ≈°√¡— ) (°‘‚≈°√¡— μÕà μ“√“߇´π쑇¡μ√) æπ◊È ∑ÀË’ πâ“μ—¥∑Ë’√∫— πÈ”Àπ—°°¥¢Õß·∑ßà ∑¥ Õ∫(μ“√“߇´π쇑 ¡μ√) 3.2 °“√§”π«≥À“§à“§«“¡Àπ“·πàπ¢Õß·∑àß∑¥ Õ∫ „Àâ¡’§«“¡≈–‡Õ¬’ ¥∂ß÷ ∑»π‘¬¡ 2 μ”·Àπàß ‰¥â ®“° μŸ √ §«“¡Àπ“·ππà ¢Õß·∑àß∑¥ Õ∫ = π”È Àπ°— ¢Õß·∑ßà ∑¥ Õ∫ (°‚‘ ≈°√—¡) (°‘‚≈°√—¡μàÕ≈°Ÿ ∫“»°‡å ´π쇑 ¡μ√) ª√‘¡“μ√¢Õß·∑àß∑¥ Õ∫ (≈Ÿ°∫“»°‡å ´π쇑 ¡μ√) À¡«¥ß“π‚§√ß √“â ß·≈–ª∞æ«’ ‘»«°√√¡ 1-53

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ 3.3 ∂â“·∑ßà ∑¥ Õ∫∑‰’Ë ¥®â “°°“√‡®“–¡ ’ à«π ŸßπâÕ¬°«“à 2 ‡∑“à ¢Õ߇ âπºà“π»Ÿπ¬°å ≈“ß„Àâ·°‰â ¢§“à §«“¡μâ“π·√ßÕ¥— μ“¡ μ“√“ß∑’Ë 1 μ“√“ß∑’Ë 1 Õ—μ√“ à«π§«“¡ ßŸ μÕà ‡ âπºà“π»Ÿπ¬°å ≈“ß°—∫μ—«§≥Ÿ ∑„Ë’ ™·â °‰â ¢§“à §«“¡μâ“π·√ßÕ¥— Õ—μ√“ à«π§«“¡ ßŸ μ«— μ§—«Ÿ≥§ Ÿ≥Ì“ À”√À∫— √·∫— °·â‰°¢â‰§¢“à §§à“«§“«¡“¥¡“â μπ“â ∑π“·π√·ß√Õߥ— Õ¥— μàÕ‡ âπºà“π»πŸ ¬å°≈“ߢÕß·∑ßà ∑¥ Õ∫ 1.75 0.99 1.50 0.97 1.25 0.94 1.00 0.91 4. °“√√“¬ß“πº≈ „Àâ√“¬ß“πº≈°“√∑¥ Õ∫ ‚¥¬¡’√“¬≈–‡Õ¬’ ¥μ“¡√“¬°“√¥ß— μÕà ‰ªπ’È - À¡“¬‡≈¢ª√–®”·∑àß∑¥ Õ∫ - ¢π“¥¢Õß·∑àß∑¥ Õ∫ - ·√ßÕ—¥ Ÿß ¥ÿ - §«“¡μâ“π·√ßÕ—¥ - ≈°— …≥–°“√·μ° - ¢Õâ ∫°æ√Õà ß ¢Õß·∑ßà ∑¥ Õ∫ À√◊Õ°“√‡§≈◊Õ∫ - ª√–«—μ°‘ “√∫à¡ - «π— ‡¥Õ◊ π ªï ∑∑Ë’ ¥ Õ∫ ·≈–Õ“¬¢ÿ Õß·∑ßà ∑¥ Õ∫ ‡¡ÕË◊ ∑¥ Õ∫ - §«“¡Àπ“·ππà ∫π— ∑÷°º≈μà“ßÊ ‡À≈“à π’È „π·∫∫øÕ√å¡„πÀ—«¢âÕ∑’Ë 2.2 5. ‡°≥±å°“√μ—¥ ‘π ·≈–§«“¡§≈“¥‡§≈Õ◊Ë π∑’¬Ë Õ¡„Àâ 5.1 ‡°≥±„å π°“√æ‘®“√≥“§à“§«“¡μ“â π·√ßÕ—¥¢Õß·∑ßà ∑¥ Õ∫„À⇪πì ‰ªμ“¡ ¡∂. 101 : ¡“μ√∞“π ß“π§Õπ°√μ’ ·≈–§Õπ°√’μ‡ √‘¡‡À≈°Á 5.2 °“√§”π«≥ §à“§«“¡μ“â π·√ßÕ—¥¢Õß·∑àß∑¥ Õ∫ „Àâ· ¥ß„πÀπ૬°‘‚≈°√¡— μÕà μ“√“ß ‡´π쑇¡μ√ ·≈–¡’§«“¡≈–‡Õ’¬¥∂ß÷ ∑»π‘¬¡ 2 μ”·Àπßà 5.3 °“√§”π«≥ §“à §«“¡Àπ“·πàπ¢Õß·∑àß∑¥ Õ∫ „À·â  ¥ß„πÀπ૬°‘‚≈°√—¡μÕà ≈°Ÿ ∫“»°å ‡´π쇑 ¡μ√ ·≈–¡’§«“¡≈–‡Õ’¬¥∂÷ß ∑»π‘¬¡ 2 μ”·Àπßà 5.4 °“√«¥— ¢π“¥¢Õß·∑ßà ∑¥ Õ∫„À«â —¥„πÀπ«à ¬‡´π쑇¡μ√ ·≈–≈–‡Õ’¬¥∂÷ß∑»π¬‘ ¡ 2 μ”·Àπàß 1-54 À¡«¥ß“π‚§√ß √â“ß·≈–ª∞æ’«‘»«°√√¡

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ 5.5  ”À√∫— ·∑àß∑¥ Õ∫√Ÿª∑√ß°√–∫Õ° ∑‰Ë’ ¥®â “°°“√À≈àÕÀ√◊Õ°“√‡®“– ¢π“¥¢Õ߇ πâ º“à π »Ÿπ¬å°≈“ß ¬Õ¡„Àâ§≈“¥‡§≈◊ËÕπ‰¥â‰¡à‡°‘π √âÕ¬≈– + 0.5 ·≈–§«“¡ Ÿß¬Õ¡„Àâ§≈“¥‡§≈◊ËÕπ‰¥â ‰¡‡à °π‘ √âÕ¬≈– + 1.0 5.6  ”À√∫— ·∑àß∑¥ Õ∫√ªŸ ≈°Ÿ ∫“»°å ¡μ‘ ‘∑ÿ°¥“â π¬Õ¡„À§â ≈“¥‡§≈◊ËÕπ‰¥â‰¡‡à °‘π √Õâ ¬≈– + 0.5 6. ¢âÕ§«√√–«ß— 6.1 „π°√≥∑’ ’∑Ë ¥ Õ∫·∑ßà ∑¥ Õ∫∑’∫Ë à¡™πÈ◊ À“°‡ªìπ·∑ßà ∑¥ Õ∫√ªŸ ≈°Ÿ ∫“»°μå âÕ߇™Á¥º‘«„Àâ·Àßâ ·≈–∑¥ Õ∫¿“¬„π 1 ™—Ë«‚¡ß ·≈–À“°‡ªìπ·∑àß∑¥ Õ∫√Ÿª∑√ß°√–∫Õ°μâÕ߇™Á¥º‘«„Àâ·Àâß ·≈–‡§≈◊Õ∫º‘«Àπ“â ·∑ßà ∑¥ Õ∫∑Èß‘ ‰«â 2 ™—Ë«‚¡ß·≈â«∑¥ Õ∫¿“¬„π 1 ™«Ë— ‚¡ß 6.2  ”À√—∫·∑àß∑¥ Õ∫∑ˉ’ ¥â®“°°“√‡®“– π”¡“·™à„ππÈ”ªŸπ¢“«Õ¡‘Ë μ—«∑Õ’Ë ≥ÿ À¿Ÿ¡À‘ âÕß ‰¡πà Õâ ¬°«“à 24 ™Ë—«‚¡ß ·≈â«®÷߇™Á¥º‘«„Àâ·Àâ߇§≈◊Õ∫º‘«Àπâ“·∑àß∑¥ Õ∫∑‘È߉«â 2 ™Ë—«‚¡ß ·≈â«∑¥ Õ∫ ¿“¬„π 1 ™—Ë«‚¡ß 6.3 °“√™Ë—ßπ”È Àπ°— ‡æ◊ËÕÀ“§«“¡Àπ“·ππà ¢Õß·∑àß∑¥ Õ∫ „Àâ™—Ëßπ”È Àπ°— ‡©æ“–·∑àß∑¥ Õ∫‰¡à√«¡ πÈ”Àπ°— ¢Õß« — ¥∑ÿ ‡’Ë §≈◊Õ∫º«‘ Àπâ“ 6.4 §«√¡’°“√μ√«® Õ∫‡§√ÕË◊ ß°¥∑„’Ë ™ßâ “πª√–®” ¡”Ë ‡ ¡Õ ªï≈–§√Èß— ·≈–‡¡ÕË◊  ß ¬— «“à ‡§√ËÕ◊ ß ∑¥ Õ∫Õ“®„Àâº≈∑¥ Õ∫‰¡à∂Ÿ°μâÕß À√◊ÕÀ≈—ß®“°°“√´àÕ¡ À√◊Õª√–°Õ∫„À¡à„Àâ∑”°“√ μ√«® Õ∫∑ÿ°§√Èß— 7. ‡Õ° “√Õ“â ßÕß‘ 7.1 THE AMERICAN ASSOCIATION OF STATE HIGHWAY OFFICIALS çSTANDARD SPECIFICATION FOR HIGHWAY MATERIALS AND METHOD OF SAMPLING AND TESTINGé AASHO T 22-66 7.2 BRITISH STANDARD 1881 : PART 4 : 1974 7.3 ¡“μ√∞“πº≈‘μ¿—≥±åÕÿμ “À°√√¡ ¡Õ°. 409-2525 : «∏‘ ∑’ ¥ Õ∫§«“¡μ“â π∑“π·√ßÕ—¥¢Õß ·∑àߧÕπ°√’μ . À¡«¥ß“π‚§√ß √â“ß·≈–ª∞æ«’ ‘»«°√√¡ 1-55

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ ‚§√ß°“√ÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇ ∫∫øø. .¡¡∑∂∂.(.(∑∑))110055.1.1-2-525050 ∑–‡∫’¬π∑¥ Õ∫ ÇÇÇÇÇ.. ÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇ..  ∂“π∑’Ë°àÕ √â“ßÇÇ.ÇÇÇÇÇÇÇÇÇÇ (Àπ૬ߓπ∑’Ë∑Ì“°“√∑¥ Õ∫) ºŸâ∑¥ Õ∫ ÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇ.. °“√∑¥ Õ∫§«“¡μâ“π·√ßÕ—¥ ºŸâμ√«® Õ∫ ºŸâ√—∫®â“ßÀ√◊ÕºŸâπÌ“ àß..ÇÇÇÇÇÇÇÇÇÇ Õπÿ¡—μ‘ ™π‘¥μ—«Õ¬à“ßÇÇÇ.Ç.∑¥ Õ∫§√—Èß∑’ËÇÇÇ ¢Õß·∑àߧÕπ°√’μ ∑¥ Õ∫«—π∑’Ë..ÇÇÇÇÇÇ.·ºàπ∑’ËÇÇÇÇ (C(OCMomPRpEreSsSsIVivEe SSTtrReEnNgGthTH §ÿ≥≈—°…≥– OFofCCOoNnCcRreEtTeE) ) æπÈ◊ ∑Ë’Àπ“â μ—¥∑Ë√’ —∫πÌÈ“Àπ°— °¥¢Õß·∑àß∑¥ Õ∫ (1) ·∑àß∑¥ Õ∫ 4 123 cm.2 πÈÌ“Àπ—°¢Õß·∑ßà ∑¥ Õ∫ (2) kg. ª√¡‘ “μ√¢Õß·∑àß∑¥ Õ∫ (3) cm.3 πÌÈ“Àπ—°°¥ Ÿß ÿ¥∑Ë’·∑ßà ∑¥ Õ∫√∫— ‰¥â (4) kg. §«“¡μâ“π·√ßÕ—¥¢Õß·∑ßà ∑¥ Õ∫ = (4)/(1), kg./cm.2 §«“¡Àπ“·πàπ¢Õß·∑ßà ∑¥ Õ∫ = (2)/(3), kg/cm3 À¡“¬‡Àμÿ : ≈—°…≥–°“√·μ°¢Õß·∑àß∑¥ Õ∫ 1-56 À¡«¥ß“π‚§√ß √â“ß·≈–ª∞æ’«»‘ «°√√¡

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ ¡∂.(∑) 105.2-2550 ¡“μ√∞“π°“√∑¥ Õ∫À“§à“°“√√—∫·√ߥ¥— ¢ÕߧÕπ°√’μ (Flexural Strength of Concrete) 1. ¢Õ∫¢à“¬ ¡“μ√∞“π°“√∑¥ Õ∫π’È §√Õ∫§≈ÿ¡∂÷ß°“√∑¥ Õ∫À“§à“°“√√—∫·√ߥ—¥¢ÕߧÕπ°√’μ ‚¥¬  “¡“√∂∑”‰¥â 2 «‘∏’ §◊Õ «‘∏’„™â·√ß°¥ÀπË÷ß®ÿ¥∑Ë’®ÿ¥°Ë÷ß°≈“ߧ“π (Center-Point Loading) ·≈–«‘∏’ „™â·√ß°¥§“π 2 ®ÿ¥ ‚¥¬„Àâμ”·ÀπàߢÕß®ÿ¥∑—Èß Õ߇ªìπμ”·Àπàß∑Ë’·∫àߧ“πÕÕ°‡ªìπ 3  à«π‡∑à“Ê °—π (Third-Point Loading) 2. «‘∏∑’ ” 2.1 ‡§√◊ËÕß¡◊Õ 2.1.1 ‡§√ÕË◊ ß°¥∑¥ Õ∫ „™â‡§√◊ËÕß°¥∑ Ë’ “¡“√∂‡æ‘¡Ë ·√ß°¥‰¥Õâ ¬à“ßμàÕ‡πËÕ◊ ß ‰¡¡à ’®—ßÀ«–À¬ÿ¥ À√◊Õ°√–μÿ°„π√–À«à“ß°“√‡æ‘Ë¡·√ß ”À√—∫°“√∑¥ Õ∫°“√√—∫·√ߥ—¥¢ÕߧÕπ°√’μ «‘∏’ „Àâ·√ß°¥Àπ÷Ëß®ÿ¥∑Ë’®ÿ¥°÷Ëß°≈“ߧ“π‰¥â· ¥ß°“√μ‘¥μȗ߇§√◊ËÕß¡◊Õ‰«â„π√Ÿª∑Ë’ 1  à«π «‘∏’„Àâ ·√ß°¥§“π Õß®ÿ¥ ‚¥¬„Àâμ”·ÀπàߢÕß®ÿ¥∑È—ß Õß ‡ªìπμ”·Àπàß∑Ë’·∫àߧ“πÕÕ°‡ªìπ 3  à«π‡∑“à Ê °π— ‰¥â· ¥ß°“√μ‘¥μ—È߇§√Ë◊Õß¡Õ◊ ‰«â„π√Ÿª∑Ë’ 2 2.1.2 ‡§√◊ËÕß«—¥¢π“¥¢Õߧ“πμ—«Õ¬“à ß ´ßË÷  “¡“√∂«¥— ‰¥≈â –‡Õ¬’ ¥∂ß÷ 0.1 ¡‘≈≈‡‘ ¡μ√ 2.2 ·∫∫øÕ√å¡ „™·â ∫∫øÕ√å¡∑’Ë ∫ø. ¡∂.(∑) 105.2-2550 : °“√∑¥ Õ∫°“√√∫— ·√ߥ—¥¢ÕߧÕπ°√’μ 2.3 °“√‡μ√¬’ ¡μ—«Õ¬“à ß °“√∑¥ Õ∫°“√√—∫·√ߥ—¥¢ÕߧÕπ°√’μ ∑”‰¥â‚¥¬°“√∑¥ Õ∫§“πμ—«Õ¬à“ß¡“μ√∞“π∑Ë’ ¡’§«“¡¬“«ª√–¡“≥ 3 ‡∑à“¢Õß à«π Ÿß ‚¥¬∑Ë—«‰ª™‘Èπμ—«Õ¬à“ß®–μâÕß¡’¢π“¥∑’Ë°”Àπ¥„Àâ„π ·μà≈–ß“π §«“¡‡∫Ë’¬ß‡∫π®“°¢π“¥∑’Ë°”Àπ¥®–μâÕ߉¡à‡°‘π 3.2 ¡‘≈≈‘‡¡μ√  ”À√—∫¢π“¥°«â“ß À√Õ◊ ≈°÷ ‡°‘π 152 ¡≈‘ ≈‡‘ ¡μ√ ¢÷πÈ ‰ª ·≈–‰¡à‡°‘π 1.6 ¡≈‘ ≈‘‡¡μ√  ”À√∫— ¢π“¥‡≈°Á °«“à πÈπ— 2.4 °“√∑¥ Õ∫ 2.4.1 «“ß™Èπ‘ ∑¥ Õ∫≈ß∫π∞“π√Õß√—∫§“π «“ßÀ—«°¥„Àμâ ”·ÀπàߢÕßÀ«— °¥ §“π·≈–∞“π√Õß §“πÕ¬àŸμ“¡°”Àπ¥ ‚¥¬«‘∏’„™â·√ß°¥ÀπË÷ß®ÿ¥∑’Ë®ÿ¥°Ë÷ß°≈“ߧ“π „Àâ®—¥μ”·Àπà߇§√◊ËÕß¡◊Õ μ“¡°”Àπ¥„π√Ÿª∑Ë’ 1  à«π°“√∑¥ Õ∫«‘∏’„™â·√ß°¥§“π Õß®ÿ¥„Àâ®—¥μ”·Àπà߇§√Ë◊Õß¡◊Õ μ“¡°”Àπ¥„π √ªŸ ∑Ë’ 2 2.4.2 ª√—∫Õ—μ√“°“√°¥‡§√Ë◊Õß∑¥ Õ∫¥«â ¬·√ߪ√–¡“≥√Õâ ¬≈– 3 ∂÷ß√âÕ¬≈– 6 ¢Õß·√ߪ√–≈—¬ (Ultimate Load) ·≈⫧àÕ¬μ√«® Õ∫º‘« —¡º— ¢Õßμ—«°¥°—∫§“π ·≈–∞“π√Õߧ“π°—∫ À¡«¥ß“π‚§√ß √“â ß·≈–ª∞æ’«»‘ «°√√¡ 1-57

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ §“π¥Ÿ«à“¡’™àÕß¢π“¥°«â“ß°«à“ 0.15 ¡‘≈≈‘‡¡μ√ „π™à«ß 25 ¡‘≈≈‘‡¡μ√ À√◊Õ‰¡à ∂â“¡’„Àâ ·μàߧÕπ°√’μ∑Ë’∫√‘‡«≥™à«ßπÈ—πÊ ¥â«¬°“√Ωπ„Àâ‡√’¬∫ ™àÕß∑Ë’¢π“¥°«â“ßπâÕ¬°«à“ 0.15 ¡‘≈≈‘‡¡μ√ „π™à«ß 25 ¡‘≈≈‘‡¡μ√ Õ“®Õÿ¥‰¥â‚¥¬°“√«“ß·ºàπÀπ—ß (Leather Shim) ‰«â √–À«à“ߺ‘« —¡º—  ·ºàπÀπ—ß∑Ë’„™â®–μâÕß¡’¢π“¥‡∑à“°—∫ 6.4 ¡‘≈≈‘‡¡μ√ °«â“ß 25 ¡≈‘ ≈‘‡¡μ√ ∂ß÷ 50 ¡‘≈≈‘‡¡μ√ 2.4.3 ‡æË¡‘ ·√ß°¥Õ¬à“ßμÕà ‡πËÕ◊ ß ·≈–‰¡à¡°’ “√°√–μÿ°„π™«à ߧ√Ë÷ß·√°¢Õß·√ߪ√–≈¬— Õ“®‡æË‘¡ ·√߉¥âÕ¬à“ß√«¥‡√Á« À≈—ß®“°π—Èπ„Àâ‡æ‘Ë¡·√ߥ⫬՗μ√“∑Ë’Õ¬àŸ„π™à«ß 9 °‘‚≈°√—¡μàÕμ“√“ß 1-58 À¡«¥ß“π‚§√ß √â“ß·≈–ª∞æ’«‘»«°√√¡

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ ‡´π쑇¡μ√μàÕπ“∑’ ∂÷ß 12 °‘‚≈°√—¡μàÕμ“√“߇´π쑇¡μ√μàÕπ“∑’ (125 ªÕπ¥åμàÕμ“√“ß π‘È«μàÕπ“∑’ ∂ß÷ 175 ªÕπ¥åμàÕμ“√“ßπ‘«È μàÕπ“∑)’ 2.4.4 «—¥¥â“π°«“â ß·≈–≈°÷ ¢Õߧ“π∑∫Ë’ √‡‘ «≥∑¡’Ë √’ Õ¬·μ°¥“â π≈– 3 §√Èß— ·≈«â À“§“à ‡©≈¬’Ë ¢Õß Àπâ“μ—¥∑Ë√’ Õ¬·μ° æ√Õâ ¡∑Èß—  ß— ‡°μ≈°— …≥–°“√·μ°√â“«¢Õߧ“πμ—«Õ¬à“ß 3. °“√§”π«≥ °“√§”π«≥§à“°“√√—∫·√ߥ—¥®–°”Àπ¥„ÀâÕ¬Ÿà„π√Ÿª¢Õß ‚¡¥Ÿ≈— ¢Õß°“√·μ°À—° (Modulus of Rupture) ¥—ßμÕà ‰ªπÈ’ 3.1  ”À√∫— °“√°¥ÀπË÷ß®¥ÿ ∑®Ë’ ÿ¥°÷Ëß°≈“ߧ“π (Center-Point Loading)  “¡“√∂À“§“à °“√ √—∫·√ߥ—¥‰¥®â “° μŸ √ R = 3 PI/2bd2 3.2  ”À√—∫°“√°¥ Õß®ÿ¥ ‚¥¬μ”·Àπßà ∑®Ë’ ¥ÿ ∑Èß—  Õß·∫ßà §“πÕÕ°‡ªìπ “¡ «à π (Third-Point Loading)  “¡“√∂À“§à“°“√√∫— ·√ߥ—¥‰¥â ®“° μŸ √ 3.2.1 ‡¡ÕË◊ √Õ¬·μ°Õ¬„àŸ π™«à ß°≈“ߧ“π R = PI/2bd2 3.2.2 ‡¡Õ◊Ë √Õ¬·μ°Õ¬πŸà Õ°™«à ß°≈“ߧ“π ·≈–À“à ß®“°™«à ß°≈“ß ‰¡‡à °‘π√âÕ¬≈– 5 ¢Õß™à«ß§“π „Àâ„™â R = 3 PI/2bd2 ‡¡Õ◊Ë R = §à“°“√√—∫·√ߥ¥— ‡ªìπ °‚‘ ≈°√—¡μÕà μ“√“߇´π쇑 ¡μ√ P = ·√ß∑Ë®’ ÿ¥«‘∫—μ‘¢Õߧ“𠇪πì °‘‚≈°√—¡ I = ™«à ߧ“𠇪ìπ ‡´π쇑 ¡μ√ b = §«“¡°«â“߇©≈’ˬ∑À’Ë πâ“μ¥— ∫√‘‡«≥√Õ¬·μ° ‡ªπì ‡´π쇑 ¡μ√ d = §«“¡≈÷°‡©≈¬Ë’ ∑Ë’Àπ“â μ¥— ∫√‘‡«≥√Õ¬·μ° ‡ªìπ ‡´π쇑 ¡μ√ a = √–¬–‡©≈ˬ’ ¢Õß√Õ¬·μ°®“°∞“π√Õߧ“π¥“â π„°≈∑â ’Ë ¥ÿ ‡ªìπ ‡´π쑇¡μ√ 4. °“√√“¬ß“πº≈ „Àâ√“¬ß“πº≈μ“¡√“¬≈–‡Õ’¬¥„π·∫∫øÕ√å¡∑’Ë ∫ø. ¡∂.(∑) 105.2-2550 : °“√∑¥ Õ∫°“√ √—∫·√ߥ¥— ¢ÕߧÕπ°√’μ À¡«¥ß“π‚§√ß √“â ß·≈–ª∞æ«’ »‘ «°√√¡ 1-59

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ 5. ‡°≥±°å “√μ¥—  π‘ ·≈–§«“¡§≈“¥‡§≈ÕË◊ π∑¬Ë’ Õ¡„Àâ 5.1 °“√æ‘®“√≥“§“à °“√√∫— ·√ߥ¥— ¢ÕߧÕπ°√μ’ μâÕßÕ¬Ÿ„à π™à«ß √Õâ ¬≈– 11 ∂÷ß√Õâ ¬≈– 23 ¢Õß §«“¡μ“â π·√ßÕ—¥¢Õß·∑ßà ∑¥ Õ∫´Ëß÷ ‡ªπì §Õπ°√μ’ ∑Ë’º ¡„π§√ßÈ— ‡¥¬’ «°π— 5.2 „π°√≥’¢Õß°“√∑¥ Õ∫«‘∏’„™â·√ß°¥§“π Õß®¥ÿ ∂â“√Õ¬·μ°Õ¬àŸπÕ°™«à ß°≈“ߧ“π·≈–À“à ß ®“°™«à ß°≈“ߧ“π‡°‘π√Õâ ¬≈– 5 ¢Õß™à«ß§“π „À∑â ”°“√∑¥ Õ∫„À¡à 5.3 §“à °“√√∫— ·√ߥ—¥ μâÕߧ”π«≥„Àâ≈–‡Õ’¬¥ ∂ß÷ 0.35 °‘‚≈°√¡— μÕà μ“√“߇´π쇑 ¡μ√ (5 ªÕπ¥å μÕà μ“√“ßπ‘È«) 6. ¢âÕ§«√√–«ß— 6.1 °“√‡æ¡‘Ë ·√ß°¥®–μÕâ ß°√–∑”Õ¬à“ßμÕà ‡π◊ËÕß ·≈–‰¡¡à ’°“√°√–μ°ÿ 6.2  ”À√—∫μ«— Õ¬à“ß∑∫’Ë à¡™◊πÈ ®–μâÕ߇™¥Á º‘«§“π¡“μ√∞“π∑Ë’®–∑¥ Õ∫„À·â Àßâ ·≈«â ∑¥ Õ∫¿“¬„π 1 ™—Ë«‚¡ß 6.3 §«√¡°’ “√μ√«® Õ∫‡§√ÕË◊ ß°¥∑’Ë„™ßâ “πÕ¬à“ß ¡Ë”‡ ¡Õ À√Õ◊ ‡¡◊ÕË  ß —¬«à“‡§√ÕË◊ ß∑¥ Õ∫Õ“®„Àâ º≈∑¥ Õ∫‰¡∂à °Ÿ μâÕßÀ√◊ÕÀ≈—ß®“°°“√´Õà ¡ À√Õ◊ ª√–°Õ∫„À¡à„Àâ∑”°“√μ√«® Õ∫∑°ÿ §√—Èß 7. ‡Õ° “√Õâ“ßÕ‘ß 7.1 AMERICAN SOCIETY OF TESTING AND MATERIALS ; ASTM STANDARD : C 78-84, C 293-79 1-60 À¡«¥ß“π‚§√ß √â“ß·≈–ª∞æ’«‘»«°√√¡

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ ‚‚§§√√ßß°°““√√Ç...Ç....Ç....Ç....Ç....Ç....Ç...Ç....Ç....Ç....Ç....Ç....Ç....Ç...Ç....... ∫øø.. ¡¡∑∂∂.(.(∑∑))110055..22--2550 ∑–‡∫’¬π∑¥ Õ∫ÇÇÇÇÇÇ Ç....Ç....Ç....Ç...Ç....Ç....Ç....Ç....Ç....Ç....Ç....Ç...Ç....Ç....Ç....Ç....Ç....Ç.......... ºŸâ∑¥ Õ∫   ∂∂““ππ∑∑’Ë°Ë°’ àÕÕà   √√â““â ßßÇ...Ç....Ç....Ç....Ç....Ç....Ç...Ç....Ç....Ç....Ç....Ç....Ç.... (Àπ૬ߓπ∑’Ë∑Ì“°“√∑¥ Õ∫) ºŸâμ√«® Õ∫ Ç....Ç....Ç....Ç...Ç....Ç....Ç....Ç....Ç....Ç....Ç....Ç...Ç....Ç....Ç....Ç....Ç....Ç....Ç.... °°““√√∑∑¥¥  ÕÕ∫∫§§««““¡¡μμâ“â“ππ··√√ßߥ¥¥— ¥— Õπÿ¡—μ‘ ºŸâ√√—∫∫— ®®â““â ßßÀÀ√√◊Õ◊ÕººŸâππ⟠̓”  àßßà Ç...Ç....Ç....Ç....Ç...Ç....Ç....Ç....Ç....Ç....Ç..... ™™ππ‘¥¥‘ μμ—««— ÕÕ¬¬à“à“ßßÇ...Ç....Ç....Ç.....Ç....∑.∑¥¥  ÕÕ∫∫§§√√—ÈßÈ—ß∑∑’ËÇË’..Ç....Ç..... ¢ÕߧÕπ°√’μ (FL(FElXeUxuRrAaLl SStTreRnEgNtGhTH ∑¥¥  ÕÕ∫∫««—ππ— ∑∑’ËÇ’Ë...Ç....Ç....Ç....Ç....Ç....Ç....·..·ººàπàπ∑∑’ËÇ’Ë..Ç....Ç....Ç...... OoFf COonNcCrRetEeT)E) °“√°¥Àπ÷Ëß®ÿ¥∑’Ë®ÿ¥°÷Ëß°≈“ߧ“𠧓π∑¥ Õ∫ (CE(CNeTnEteRr--PPOoIiNntTLLoOaAdiDnIgN)G) 1234 ·√ß∑’®Ë ÿ¥«‘∫—μ‘¢Õߧ“π (P) kg. ™à«ß§“π (I) cm. §«“¡°«â“߇©≈’ˬ∑ËÀ’ π“â μ¥— ∫√‡‘ «≥√Õ¬·μ° (b) cm. §«“¡≈÷°‡©≈’ˬ∑’ËÀπâ“μ—¥∫√‘‡«≥√Õ¬·μ° (d) cm. §à“°“√√—∫·√ߥ¥— (R) = 3 PI/2bd2 kg./cm.2 °“√°¥ Õß®ÿ¥‚¥¬μÌ“·Àπàß∑’Ë®ÿ¥∑—Èß Õß·∫àߧ“𠧓π∑¥ Õ∫ ÕÕ°‡ªìπ “¡ à«π (THIRD-POINT LOADING) 1234 ·√ß∑Ë’®¥ÿ «∫‘ —μ‘¢Õߧ“π (P) kg. ™à«ß§“π (I) cm. §«“¡°«â“߇©≈’¬Ë ∑’ÀË π“â μ¥— ∫√‡‘ «≥√Õ¬·μ° (b) cm. §«“¡≈°÷ ‡©≈ˬ’ ∑ËÀ’ πâ“μ¥— ∫√‘‡«≥√Õ¬·μ° (d) cm. √–¬–‡©≈¬Ë’ ¢Õß√Õ¬·μ°®“°∞“π√Õߧ“π¥â“π„°≈∑â  Ë’ ÿ¥ (a) cm. §à“°“√√—∫·√ߥ—¥ (√Õ¬·μ°√â“«Õ¬ŸàπÕ°™à«ß°≈“ߧ“π) (R) = 3PI/2bd2 kg./cm.2 §à“°“√√—∫·√ߥ—¥ (√Õ¬·μ°√â“«Õ¬àŸ„π™«à ß°≈“ߧ“π) (R) = PI/2bd2 kg./cm.2 À¡“¬‡Àμÿ : À¡«¥ß“π‚§√ß √â“ß·≈–ª∞æ«’ »‘ «°√√¡ 1-61

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ ¡∂.(∑) 201-2550 ¡“μ√∞“π°“√∑¥ Õ∫À“§à“·√ßÕ¥— „π·π«μ—ßÈ ©“°‡ ’Ȭπ¢Õ߉¡â (Compression Test of Wood Perpendicular to Grain) 1. ¢Õ∫¢“à ¬ ¡“μ√∞“π°“√∑¥ Õ∫π’È §√Õ∫§≈ÿ¡∂÷ß°“√À“§ÿ≥ ¡∫—μ‘∑“ß°≈¢Õ߉¡â¥â«¬Õ—μ√“·√ßÕ—¥„π ·π«μß—È ©“°‡ ¬’È π ·≈–¥Ÿæƒμ‘°√√¡¢Õ߉¡â ‡¡ËÕ◊ ∂°Ÿ ·√ß°√–∑” ·≈–æ‘®“√≥“À“§“à ∑Ëμ’ âÕß°“√ §◊Õ 1.1 °”≈ß— Õ—¥¢Õ߉¡â ≥ ¢’¥ªØ¿‘ “§ (Elastic Strength at Proportional Limit) 1.2 °”≈ß— Õ¥— ¢Õ߉¡â ≥ ®¥ÿ §≈“° ∑Ë’ 0.05% Offset (Yielding Strength at 0.05% Offset) 1.3 ‚¡¥≈Ÿ — ¬◊¥À¬àÿπ (Modulus of Elasticity) 2. 𑬓¡ §«“¡À¡“¬¢Õߧ”∑Ë’„™â„π¡“μ√∞“π°“√∑¥ Õ∫‰¡âπÈ’ „À⇪ìπ‰ªμ“¡¡“μ√∞“πº≈‘μ¿—≥±å Õÿμ “À°√√¡ ¡Õ°. 421 ‰¡â·ª√√Ÿª : ¢Õâ °”Àπ¥∑—«Ë ‰ª 3. ™È—π§ÿ≥¿“æ·≈– —≠≈—°…≥å „À⇪ìπ‰ªμ“¡¡“μ√∞“πº≈‘μ¿—≥±åÕÿμ “À°√√¡ ¡Õ°. 424 ‰¡â·ª√√Ÿª :  ”À√—∫ß“π °àÕ √“â ß∑—«Ë ‰ª 4. «∏‘ ’∑” 4.1 ‡§√ËÕ◊ ß¡◊Õ·≈–Õÿª°√≥å ª√–°Õ∫¥«â ¬ ‰¡‚§√¡‘‡μÕ√å™π‘¥¡’Àπ⓪í∑¡å (Dial Gauge) ∑Ë’«—¥‰¥â≈–‡Õ’¬¥∂÷ß 0.001 ¡¡. æ√âÕ¡¥â«¬·ºàπ ‡À≈Á°√Õß√—∫ (Dial Micrometer with Bearing Block) ¥—ß· ¥ß„π√ªŸ ∑Ë’ 1 ‰¡‚§√¡‡‘ μÕ√å™π¥‘ ¡’Àπ“â ªí¥ ·ºàπ‡À≈Á°°¥ ‰¡μâ —«Õ¬“à ß ·ºàπ‡À≈Á°√Õß√—∫ √Ÿª∑’Ë 1 · ¥ß‡§√ËÕ◊ ß¡◊Õ·≈–Õÿª°√≥å °“√∑¥ Õ∫À“§à“·√ßÕ¥— „π·π«μ—Èß©“°‡ ¬È’ π¢Õ߉¡â 1-62 À¡«¥ß“π‚§√ß √“â ß·≈–ª∞æ«’ ‘»«°√√¡

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ 4.2 °“√‡μ√¬’ ¡μ—«Õ¬“à ß°“√∑¥ Õ∫ ‡μ√’¬¡‰¡âμ—«Õ¬à“ß∑Ë’‰ ‡√’¬∫ (Dressed Timber) ·≈–‡°≈’È¬ß (Clear Wood) ¢π“¥ 5x5x15 ´¡. ™π‘¥≈– 3 ∑àÕπ‚¥¬‰¡âμ—«Õ¬à“ß∑’Ë®–π”¡“∑¥ Õ∫μâÕß¡’§à“§«“¡™È◊π (Moisture Content) Õ¬√Ÿà –À«à“ß√Õâ ¬≈– 10 ∂÷ß √âÕ¬≈– 14 4.3 ·∫∫øÕ√å¡ „™â·∫∫øÕ√å¡∑Ë’ ∫ø. ¡∂.(∑) 201.1-2550 : °“√∑¥ Õ∫À“§à“·√ßÕ—¥„π·π«μÈ—ß©“°‡ È’¬π ¢Õ߉¡â , 201.2-2550 : °“√∑¥ Õ∫À“§“à ·√ßÕ—¥„π·π«μÈß— ©“°‡ ¬’È π¢Õ߉¡â 4.4 °“√∑¥ Õ∫ 4.4.1 ‰¡âμ«— Õ¬à“ß∑∑Ë’ ”°“√∑¥ Õ∫ μâÕß∑”‡ªìπ∑àÕπ ‡Ë’ À≈’ˬ¡¡‡’ πÈÕ◊ ∑’ËÀπ“â μ—¥‡∑“à °—πμ≈Õ¥§«“¡¬“« ·≈–·π«‡ ’¬È π‰¡μâ ßÈ— ©“°°∫— ·°π‰¡â ‚¥¬¡’·ºπà ‡À≈°Á √Õß√∫— ∑“â ¬¢Õ߉¡μâ «— Õ¬à“ß 4.4.2 «¥— ¢π“¥¢Õ߉¡âμ«— Õ¬“à ß ‚¥¬¬Õ¡„Àºâ ‘¥æ≈“¥‰¥â‰¡‡à °‘π 0.2 ¡.¡. ·≈–™ß—Ë π”È Àπ°— Õà“π§à“ ≈–‡Õ¬’ ¥‰¥‡â ªπì °√¡— æ√Õâ ¡∑—Èß· ¥ß√Õ¬μ”Àπμ‘ “à ßÊ ¢Õ߉¡∑⠪˒ √“°Ø„Àâ‡ÀÁπ 4.4.3 «“߉¡âμ—«Õ¬à“ß∫π·ºπà ‡À≈°Á √Õß√—∫ (Bearing Block) ‚¥¬„Àâ·π«‡ ’ȬπÕ¬à„Ÿ π·π« √–¥—∫ ·≈– „À⺑«¥â“πμÈ—ß©“°°—∫«ßªï (Radial) Õ¬ŸàμÕπ∫π ÿ¥ ∫—π∑÷°§«“¡°«â“ߢÕߺ‘« ¥â“ππÈ’ «“ß·ºàπ‡À≈Á°°¥ (Loading Plate) ¢π“¥ 2 π‘È« ´÷Ëß„™â√Õß√—∫πÈ”Àπ—°∑’Ë°¥≈ß ‚¥¬«“ßμ“¡·π«¢«“ß„À≥â°÷Ëß°≈“ß ª√–¡“≥ 1/3  à«π¢Õߧ«“¡¬“«‰¡âμ—«Õ¬à“ß ‚¥¬ „À·â 𫬓«¢Õß·ºàπ‡À≈°Á °¥ ∑”¡¡ÿ ©“°°∫— ·π«¬“«¢Õ߉¡âμ—«Õ¬à“ß 4.4.4 ª√—∫√–¬–§«“¡ ßŸ ¢Õ߉¡‚§√¡‡‘ μÕ√å™π¥‘ ¡’μ—«‡≈¢∫πÀπ“â ªí∑¡å ‚¥¬„Àªâ ≈“¬·°π¢Õß ‰¡‚§√¡‘‡μÕ√å  ¡— º— °—∫º«‘ ¢Õ߉¡μâ «— Õ¬“à ߇≈°Á πÕâ ¬ 4.4.5 „ÀâπÈ”Àπ—°°¥≈ߧ√È—ß·√° 100 °‚‘ ≈°√—¡ ·≈–ª√∫— ‡¢Á¡∑À’Ë π⓪í∑¡¢å Õ߉¡‚§√¡‡‘ μÕ√å „Àâ™’È ∑’¢Ë ¥’ »πŸ ¬å 4.4.6 ‡æ¡Ë‘ ·√ß°¥∫π‰¡μâ «— Õ¬à“ßÕ¬à“ßμÕà ‡π◊ËÕߥ⫬§«“¡‡√«Á ª√–¡“≥ 0.5 ¡¡.μàÕπ“∑’ Õ“à π§“à °“√À¥μ—« (Deformation) ∑Ë’Àπ⓪í∑¡å¢Õ߉¡‚§√¡‘‡μÕ√å ∑ÿ°Ê §√È—ß∑Ë’‡æË‘¡πÈ”Àπ—°°¥ 100 °‘‚≈°√—¡ ®π°«à“‡¢Á¡∑Ë’Àπ⓪í∑¡å®–À¡ÿπ‰ª§√∫ 2 √Õ∫ (2 ¡‘≈≈‘‡¡μ√) À√◊Õ‡¢Á¡∑Ë’ Àπ⓪∑í ¡å‡√Ë‘¡À¡πÿ ‰ªÕ¬à“ß√«¥‡√«Á ‚¥¬‰¡Àà ¬ÿ¥ 4.4.7 ‡¢’¬π°√“ø ‚¥¬°”Àπ¥„À·â √ß°¥ Õ¬Ÿ∫à π·°πμÈ—ß·≈–°“√À¥μ—«¢Õ߉¡â Õ¬à∫Ÿ π·°ππÕπ „Àâ· ¥ß§à“°”≈—ßÕ—¥ ≥ ¢’¥ªØ‘¿“§ ·≈–°”≈—ß ≥ ®ÿ¥§≈“° (· ¥ß¥â«¬‡ âπ°√“ø Oû-Aû) ∫π°√“ø¥â«¬ ∂Ⓡ âπ°√“ø‰¡àºà“π®ÿ¥‡√‘Ë¡μâπ„Àâª√—∫·°â„À¡à ‚¥¬„Àâºà“π®ÿ¥‡√‘Ë¡μâπ (· ¥ß¥«â ¬‡ πâ °√“ø O-A) ¥—ß· ¥ß„π√ªŸ ∑Ë’ 2 À¡«¥ß“π‚§√ß √â“ß·≈–ª∞æ«’ ‘»«°√√¡ 1-63

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ √Ÿª∑’Ë 2 °√“ø· ¥ß§«“¡ —¡æπ— ∏å√–À«à“ß·√ß°¥·≈–°“√À¥μ«— ¢Õ߉¡â 5. °“√§”π«≥ „À⥔‡π‘π°“√§”π«≥μ“¡«‘∏’∑Ë°’ ”À𥉫„â π·∫∫øÕ√¡å μ“¡¢Õâ 4.3 6. °“√√“¬ß“π „Àâ√“¬ß“πμ“¡·∫∫øÕ√å¡ ∫ø. ¡∂.(∑) 201.1-2550 : °“√∑¥ Õ∫À“§à“·√ßÕ—¥„π·π«μ—Èß ©“°‡ ¬È’ π¢Õ߉¡â , 201.2-2550 : °“√∑¥ Õ∫À“§à“·√ßÕ¥— „π·π«μßÈ— ©“°‡ ¬’È π¢Õ߉¡â 7. ‡°≥±°å “√μ—¥ π‘ ·≈–§«“¡§≈“¥‡§≈◊ÕË π∑’¬Ë Õ¡„Àâ ‡°≥±å°“√μ—¥ ‘π„™â§à“‡©≈Ë’¬°“√∑¥ Õ∫À“§à“·√ßÕ—¥„π·π«μÈ—ß©“°‡ È’¬π¢Õ߉¡â ·μà≈–™π‘¥ (μ“¡¢âÕ 5, 6 ·≈– 7 „π·∫∫øÕ√å¡ ∫ø. ¡∂.(∑) 201.1-2550 : °“√∑¥ Õ∫À“§à“·√ßÕ—¥„π·π«μÈ—ß ©“°‡ ¬’È π¢Õ߉¡)â 8. ¢âÕ§«√√–«ß— 8.1 §“à ∑’ËÕà“π‰¥®â “°‡§√ÕË◊ ß¡Õ◊ ∑¥ Õ∫ μâÕ߇ªπì §“à ∑’ËÕ“à π‰¥≈â –‡Õ’¬¥ ·≈–∂°Ÿ μâÕß 8.2 ‰¡μâ «— Õ¬“à ß∑Ë®’ –π”¡“∑¥ Õ∫ μÕâ ßÕ¬Ÿà„π ¿“æ∑ ’Ë ¡∫Ÿ√≥å‡√’¬∫√âÕ¬ ¡¢’ π“¥μ“¡∑’Ë°”Àπ¥‡∑à“ °π— μ≈Õ¥∑—ßÈ ∑àÕπ ·≈–μÕâ ߉¡à¡’μ”Àπ„‘ π‡πÕ◊È ‰¡â 8.3 ‰¡âμ—«Õ¬à“ß∑’®Ë –π”¡“∑¥ Õ∫μÕâ ß«“ß„πμ”·Àπßà ∑’Ë∂Ÿ°μÕâ ß ·≈–¡—πË §ßμ“¡·π«∑’°Ë ”Àπ¥ 8.4 ·ºàπ‡À≈Á°°¥·≈–·ºπà ‡À≈Á°√Õß√∫— ‰¡âμ—«Õ¬“à ß μâÕßÕ¬„Ÿà πμ”·Àπàß∑ˉ’ ¡à„À⇧≈ËÕ◊ πμ«— ‰¥â 8.5  ∂“π∑Ë’∑¥ Õ∫μâÕ߇ªìπ∑Ë∑’ Ë’‰¡à¡’§«“¡ π—Ë  –‡∑◊Õπ¡“°‡æ√“–®–∑”„Àâ§à“∑Ë’Õà“π®“°‡§√◊ËÕß ∑¥ Õ∫¡§’ «“¡º¥‘ æ≈“¥‰¥âß“à ¬ 8.6 °“√‡æË¡‘ ·√ß°¥≈ß∫π‰¡μâ «— Õ¬à“ß À“â ¡‡æ‘¡Ë ·√ß°¥Õ¬“à ß√«¥‡√Á« „À⥔‡π‘π°“√‡æ¡Ë‘ ·√ß°¥∑’≈– πâÕ¬Õ¬à“ß™â“Ê 1-64 À¡«¥ß“π‚§√ß √“â ß·≈–ª∞æ’«»‘ «°√√¡

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ 9. Àπß—  Õ◊ Õ“â ßÕ‘ß 9.1 ¡“μ√∞“πº≈‘μ¿≥— ±åÕÿμ “À°√√¡ ¡Õ°. 421-2525 ‰¡·â ª√√ªŸ : ¢âÕ°”Àπ¥∑Ë«— ‰ª 9.2 ¡“μ√∞“πº≈‘μ¿—≥±åÕμÿ  “À°√√¡ ¡Õ°. 424-2530 ‰¡·â ª√√Ÿª :  ”À√∫— ß“π°Õà  √â“ß∑«Ë— ‰ª 9.3 FACULTY OF ENGINEERING CHULALONGKORN UNIVERSITY MATERIAL TESTING LABORATORY TEST NO.T 3 (COMPRESSION TEST OF WOOD PERPENDICULAR TO GRAIN) 9.4 ASTM DESIGNATION D 143-83 STANDARD METHODS OF TESTING SMALL CLEAR SPECIMENS OF TIMBER. 9.5 HARMER E. DAVIS, GEORGE EARL TROXELL AND CLEMENT T. WISKOCIL THE TESTING AND INSPECTION OF ENGINEERING MATERIALS (THIRD EDITION) 9.6 FREDERICK F. WANGAARD THE MECHANICAL PROPERTIES OF WOOD. À¡«¥ß“π‚§√ß √“â ß·≈–ª∞æ’«»‘ «°√√¡ 1-65

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°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ ¡∂.(∑) 202-2550 ¡“μ√∞“π°“√∑¥ Õ∫À“§à“·√ßÕ¥— „π·π«¢π“π‡ È¬’ π¢Õ߉¡â (Compression Test of Wood Parallel to Grain) 1. ¢Õ∫¢“à ¬ ¡“μ√∞“π°“√∑¥ Õ∫πÈ’ §√Õ∫§≈ÿ¡∂÷ß°“√À“§ÿ≥ ¡∫—μ‘∑“ß°≈¢Õ߉¡â¥â«¬Õ—μ√“·√ßÕ—¥„π ·π«¢π“π‡ ’È¬π ·≈–¥Ÿæƒμ‘°√√¡¢Õ߉¡â ‡¡◊ËÕ∂Ÿ°·√ß°√–∑” μ≈Õ¥®π»÷°…“≈—°…≥–°“√·μ°¢Õß ‰¡â (Failure) ‡¡Õ◊Ë ∂ß÷ ®ÿ¥«‘∫μ— ·‘ ≈â«·≈–æ‘®“√≥“À“§“à ∑Ëμ’ âÕß°“√ §◊Õ 1.1 °”≈—ßÕ¥— ¢Õ߉¡â ≥ ¢¥’ ªØ‘¿“§ (Elastic Strength at Proportional Limit) 1.2 °”≈—ßÕ—¥¢Õ߉¡â ≥ ®ÿ¥§≈“°∑’Ë 0.05% Offset (Yielding Strength At 0.05% Offset) 1.3 °”≈—ßÕ¥— ª√–≈—¬¢Õ߉¡â (Ultimate Strength) 1.4 ‚¡¥≈Ÿ  — ¬¥◊ À¬πàÿ (Modulus of Elasticity) 2. 𑬓¡ §«“¡À¡“¬¢Õߧ”∑Ë’„™â„π¡“μ√∞“π°“√∑¥ Õ∫‰¡âπÈ’ „À⇪ìπ‰ªμ“¡¡“μ√∞“πº≈‘μ¿—≥±å Õÿμ “À°√√¡ ¡Õ°. 421 ‰¡â·ª√√Ÿª : ¢Õâ °”Àπ¥∑Ë«— ‰ª 3. ™Èπ— §≥ÿ ¿“æ·≈– ≠— ≈°— …≥å „À⇪ìπ‰ªμ“¡¡“μ√∞“πº≈‘μ¿—≥±åÕÿμ “À°√√¡ ¡Õ°. 424 ‰¡â·ª√√Ÿª :  ”À√—∫ß“π °Õà  √“â ß∑—«Ë ‰ª 4. «‘∏∑’ ” 4.1 ‡§√◊ËÕß¡Õ◊ ·≈–Õÿª°√≥å ª√–°Õ∫¥â«¬ 4.1.1 ‡§√ÕË◊ ß¡◊Õ∑¥ Õ∫‰¡â 4.1.2 ‡§√◊ËÕß¡Õ◊ «¥— °“√À¥μ—«¢Õ߉¡™â π‘¥∑Ë’¡§’ «“¡¬“«æ°‘ —¥ 15 ´¡. ( Compressometer Having 15 CM. Gauge Length ) ¥—ß· ¥ß„π√Ÿª∑’Ë 1 4.2 °“√‡μ√¬’ ¡μ—«Õ¬“à ß°“√∑¥ Õ∫ ‡μ√’¬¡‰¡μâ «— Õ¬à“ß∑’ˉ ‡√¬’ ∫ (Dressed Timber) ·≈– ‡°≈È’¬ß (Clear Wood) ¢π“¥ 5x5x20 ´¡. ™π‘¥≈– 3 ∑àÕπ ‚¥¬‰¡âμ—«Õ¬à“ß∑Ë’®–π”¡“∑¥ Õ∫ μâÕß¡’§à“§«“¡™È◊π (Moisture Content) Õ¬Ÿà√–À«à“ß√âÕ¬≈– 10 ∂ß÷ √âÕ¬≈– 14 4.3 ·∫∫øÕ√å¡ „™â·∫∫øÕ√å¡∑’Ë ∫ø. ¡∂.(∑) 202.1-2550 : °“√∑¥ Õ∫À“§à“·√ßÕ—¥„π·π«¢π“π‡ ’È¬π ¢Õ߉¡,â 202.2-2550 : °“√∑¥ Õ∫À“§“à ·√ßÕ¥— „π·π«¢π“π‡ È’¬π¢Õ߉¡â 1-68 À¡«¥ß“π‚§√ß √â“ß·≈–ª∞æ«’ ‘»«°√√¡

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ ‰¡‚§√¡‡‘ μÕ√™å 𥑠¡À’ π⓪∑í ¡å ‰¡âμ«— Õ¬“à ß ‡§√◊ÕË ß«¥— °“√À¥μ«— ¢Õ߉¡â™π‘¥∑’Ë¡§’ «“¡¬“«æ‘°¥— 15 ´¡. √Ÿª∑Ë’ 1 · ¥ß‡§√Õ◊Ë ß¡Õ◊ ·≈–Õÿª°√≥°å “√∑¥ Õ∫À“§“à ·√ßÕ—¥„π·π«¢π“π‡ È¬’ π¢Õ߉¡â 4.4 °“√∑¥ Õ∫ 4.4.1 ‰¡μâ —«Õ¬“à ß∑’Ë∑”°“√∑¥ Õ∫ μÕâ ß∑”‡ªìπ∑Õà π Ë’‡À≈ˬ’ ¡¡‡’ πÕÈ◊ ∑ËÀ’ πâ“∑’Ëμ¥— ‡∑“à °—πμ≈Õ¥ §«“¡¬“« ·≈–„π·π«‡ È’¬π‰¡â¢π“π°—∫·°π‰¡â ‚¥¬¡’·ºàπ‡À≈Á°√Õß√—∫∑⓬¢Õ߉¡â μ—«Õ¬“à ß 4.4.2 «—¥¢π“¥Àπâ“μ—¥‰¡âμ«— Õ¬“à ß‚¥¬¬Õ¡„À⺑¥æ≈“¥‰¥â‰¡à‡°‘π 0.2 ¡.¡.«¥— §«“¡¬“«‚¥¬ ¬Õ¡„À⺑¥æ≈“¥‰¥â‰¡à‡°‘π 0.5 ¡.¡.. ·≈–™Ë—ßπÈ”Àπ—°Õà“π§à“≈–‡Õ’¬¥‰¥â‡ªìπ°√—¡ æ√âÕ¡ ∑Èß— · ¥ß√Õ¬μ”Àπμ‘ “à ßÊ ¢Õ߉¡â∑ªË’ √“°Ø„Àâ‡ÀπÁ 4.4.3 μ√«® Õ∫‡§√Ë◊Õß¡Õ◊ «¥— °“√À¥μ—«¢Õ߉¡â ∑Ë’«—¥‰¥â≈–‡Õ¬’ ¥∂÷ß 0.001 ¡.¡. ·≈–μ√«®  Õ∫§«“¡¬“«æ‘°¥— (Gauge Length) ¢Õ߇§√Ë◊Õß¡◊Õ«—¥°“√À¥μ«— ¢Õ߉¡â 4.4.4 μ‘¥μÈß— ‡§√Ë◊Õß¡◊Õ«¥— °“√À¥μ«— ¢Õ߉¡â‡¢â“°∫— ‰¡μâ —«Õ¬“à ß ‚¥¬«“߉¡âμ—«Õ¬à“ß„À‰â ¥â »Ÿπ¬å°≈“ß °—∫‡§√Ë◊Õß¡◊Õ∑¥ Õ∫ æ√âÕ¡∑—Èߪ√—∫‡§√◊ËÕß¡◊Õ°¥‰¡â ·≈–‡§√Ë◊Õß¡◊Õ«—¥°“√À¥ μ—«¢Õ߉¡â „ÀÕâ “à π∑¢Ë’ ’¥»πŸ ¬å 4.4.5 ‡æ¡Ë‘ ·√ß°¥∫π‰¡μâ —«Õ¬à“ß Õ¬“à ßμàÕ‡πË◊Õߥ⫬§«“¡‡√Á«ª√–¡“≥ 0.6 ¡.¡.μàÕπ“∑’ 4.4.6 ∫—π∑°÷ ·√ß∑’°Ë ¥·≈–«¥— °“√À¥μ«— (Deformation) ¢Õ߉¡μâ —«Õ¬à“ß∑ÿ°Ê 500 °°. ¢Õß·√ß∑Ë’°¥ ®π°√–∑—Ë߇°‘π™à«ß¢Õߢ’¥ªØ‘¿“§ À≈—ß®“°π—Èπ„Àâ∂Õ¥‡§√◊ËÕß¡◊Õ«—¥°“√À¥ μ—«¢Õ߉¡âÕÕ° ·≈â«°¥‰¡âμ—«Õ¬à“߉ª®π∂÷ß®ÿ¥«‘∫—μ‘ æ√âÕ¡∑È—ß∫—π∑÷°§à“¢Õß·√ß∑’Ë°¥  Ÿß ÿ¥ 4.4.7 ∫π— ∑°÷ ≈—°…≥–°“√«∫‘ —μ‘ æ√âÕ¡∑ßÈ— ‡¢’¬π¿“æ√Õ¬·μ°¢Õ߉¡âμ—«Õ¬à“ß·μà≈–™‘Èπ ´Ë÷ß μ—«Õ¬à“ß≈—°…≥–°“√·μ°¢Õ߉¡â ¥ß— · ¥ß„π√ªŸ ∑’Ë 2 À¡«¥ß“π‚§√ß √â“ß·≈–ª∞æ’«‘»«°√√¡ 1-69

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ √Õ¬·μ°·∫∫∫¥¬Õà ¬ √Õ¬·μ°√Ÿª≈¡‘Ë √Õ¬·μ°·∫∫·√߇©Õ◊ π (Crushing) (Wedge Split) (Shearing) √Õ¬·μ°·∫∫©°’ ª≈“¬ √Õ¬·μ°·∫∫·√ßÕ¥— ·≈–·√߇©Õ◊ π¢π“π‡ ’È¬π √Õ¬·μ°·∫∫·¬°ª≈“¬ (Splitting) (Compression And Shearing Parallel To Grain) (Brooming Or End-Rolling) √Ÿª∑’Ë 2 · ¥ßμ«— Õ¬à“ß≈—°…≥–°“√«∫‘ —μ‘ 4.4.7.1 √Õ¬·μ°·∫∫∫¥¬Õà ¬ ‡°¥‘ ¢÷Èπ‡¡ÕË◊ √Õ¬·μ°Õ¬à„Ÿ π·π«¢π“π‡ ¬’È π 4.4.7.2 √Õ¬·μ°√ªŸ ≈‘Ë¡ ‡°¥‘ ¢÷Èπ‡¡◊ÕË ≈°— …≥–°“√·μ°§≈“â ¬√ªŸ ≈Ë‘¡ ‚¥¬‡ πâ ∑Ë’∂°Ÿ ºà“Õ“® ‡ªπì ‰¥∑â —Èß„π·π«‡ π⠫ߪï À√◊Õ·π«‡ πâ  ¡— º — «ßªï 4.4.7.3 √Õ¬·μ°·∫∫·√߇©Õ◊ π ‡°¥‘ ¢π÷È ‡¡◊ÕË √Õ¬·μ°∑”¡¡ÿ ¡“°°«“à 45 Õß»“ °—∫¥“â π ∫π¢Õ߉¡âμ—«Õ¬à“ß 4.4.7.4 √Õ¬·μ°·∫∫©’°ª≈“¬ ‡°‘¥¢È÷π‡¡ËÕ◊ ‰¡âμ«— Õ¬“à ß¡’μ”Àπ¿‘ “¬„π¡“°Õà π 4.4.7.5 √Õ¬·μ°·∫∫·√ßÕ¥— ·≈–√Õ¬·μ°·∫∫·√߇©◊Õπ¢π“π‡ È’¬π ‡°‘¥¢Èπ÷ ‡¡ËÕ◊ ¡’√Õ¬ ·μ°ª√“°Ø„π·π«¢«“߇ ’Ȭπ 4.4.7.6 √Õ¬·μ°·∫∫·¬°ª≈“¬ ‡°‘¥¢÷πÈ ‡πË◊Õß®“°∫√‡‘ «≥ à«πª≈“¬¢Õ߇πÕ◊È ‰¡â¡’ §«“¡™◊πÈ ¡“°‡°‘π‰ª À√Õ◊ ‡°¥‘ ®“°°“√μ¥— ‰¡âμ—«Õ¬à“ß¡“‰¡à¥æ’ Õ 4.4.8 ‡¢¬’ π°√“ø ‚¥¬°”Àπ¥„Àâ·√ß°¥ Õ¬Ÿ∫à π·°πμ—ßÈ ·≈–°“√À¥μ«— ¢Õ߉¡â Õ¬Ÿà∫π·°ππÕπ „Àâ· ¥ß§à“°”≈—ßÕ—¥ ≥ ¢’¥ªØ‘¿“§ ·≈–°”≈—ß ≥ ®ÿ¥§≈“° (· ¥ß¥â«¬‡ âπ°√“ø Oû-Aû) ∫π°√“ø¥â«¬∂Ⓡ âπ°√“ø‰¡àºà“π®ÿ¥‡√Ë‘¡μâπ„Àâª√—∫·°â„À¡à ‚¥¬„Àâºà“π®ÿ¥‡√Ë‘¡μâπ (· ¥ß¥â«¬‡ âπ°√“ø O-A) ¥ß— · ¥ß„π√Ÿª∑’Ë 3 1-70 À¡«¥ß“π‚§√ß √â“ß·≈–ª∞æ’«‘»«°√√¡

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ √ªŸ ∑Ë’ 3 °√“ø· ¥ß§«“¡ ¡— æ—π∏å√–À«à“ß·√ß°¥·≈–°“√À¥μ—«¢Õ߉¡â 5. °“√§”π«≥ „À⥔‡π‘π°“√§”π«≥μ“¡«∏‘ ∑’ Ë°’ ”À𥉫„â π·∫∫øÕ√å¡ μ“¡¢Õâ 4.3 6. °“√√“¬ß“π „À√â “¬ß“πμ“¡·∫∫øÕ√¡å „π¢âÕ 4.3 7. ‡°≥±°å “√μ—¥ π‘ ·≈–§«“¡§≈“¥‡§≈Õ◊Ë π∑Ë’¬Õ¡„Àâ ‡°≥±å°“√μ—¥ ‘π„™â§à“‡©≈Ë’¬°“√∑¥ Õ∫À“§à“·√ßÕ—¥„π·π«¢π“π‡ È’¬π¢Õ߉¡â ·μà≈–™π‘¥ (μ“¡¢âÕ 6,7,8 ·≈– 9 „π·∫∫øÕ√å¡ ∫ø. ¡∂.(∑) 202.1-2550 : °“√∑¥ Õ∫À“§à“·√ßÕ—¥„π·π« ¢π“π‡ È¬’ π¢Õ߉¡â) 8. Àπ—ß ◊ÕÕ“â ßÕ‘ß 8.1 ¡“μ√∞“πº≈‘μ¿—≥±åÕμÿ  “À°√√¡ ¡Õ°. 421-2525 ‰¡â·ª√√Ÿª : ¢Õâ °”Àπ¥∑Ë—«‰ª 8.2 ¡“μ√∞“πº≈μ‘ ¿≥— ±Õå ÿμ “À°√√¡ ¡Õ°. 424-2530 ‰¡â·ª√√ªŸ :  ”À√∫— ß“π°Õà  √“â ß∑«—Ë ‰ª 8.3 HARMER E. DAVIS, GEORGE EARL TROXELL AND CLEMENT T. WISKOCIL THE TESTING AND INSPECTION OF ENGINEERING MATERIALS (THIRD EDITION) À¡«¥ß“π‚§√ß √â“ß·≈–ª∞æ’«‘»«°√√¡ 1-71

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ ‚§√ß°“√ÇÇÇÇÇÇÇÇÇÇÇÇÇÇ.. ∫ø.¡¡∑∂..((∑∑)) 220022..11--22555500 ∑–‡∫’¬π∑¥ Õ∫ÇÇÇÇÇÇÇ  ∂“π∑’Ë°àÕ √â“ßÇ.ÇÇÇÇÇÇÇÇÇ.Ç. ºŸâ∑¥ Õ∫ ÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇ (Àπ૬ߓπ∑’Ë∑Ì“°“√∑¥ Õ∫) ºŸâμ√«® Õ∫ ºŸâ√—∫®â“ßÇÇÇÇÇÇÇÇÇÇÇÇ.ÇÇ.. °“√∑¥ Õ∫À“§à“ ºŸâÕπ¡ÿ —μ‘ ºŸâπÌ“ àßÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇ. ™π‘¥μ—«Õ¬à“ß.ÇÇÇÇ..∑¥ Õ∫§√—Èß∑’ËÇÇ.. ·√ßÕ—¥„π·π«¢π“π‡ ’È¬π¢Õ߉¡â ∑¥ Õ∫«—π∑’ËÇÇÇÇÇÇÇÇ·ºàπ∑’ËÇ..Ç ™π‘¥‰¡âμ—«Õ¬à“ß √“¬≈–‡Õ’¬¥ ‰¡âÇ..ÇÇÇÇ ‰¡âÇÇÇÇÇÇ ‰¡âÇÇÇÇÇÇ 123 1 231 2 3 æ◊Èπ∑’ÀË πâ“μ—¥μ«— Õ¬à“ß, (´¡.2) 1.¡‘μ‘¢Õ߉¡âμ—«Õ¬à“ß §«“¡¬“«¢Õ߉¡,â L (´¡.) 2.§«“¡¬“«æ‘°—¥ (´¡.) 3.π.π.¢Õ߉¡âμ—«Õ¬“à ß (°°.) 4.·√ß°¥ ≥ ®ÿ¥§≈“° ∑’Ë 0.05% OFFSET , Py (°°.) 5.·√ß°¥ ≥ ®ÿ¥«∫‘ —μ‘ PMax (°°.) 6.§«“¡‡§âπ¢Õ߉¡â ∑Ë’ P.L. (°°./´¡.2) S = ·√ß°¥∑Ë’ P.L. / A 7.°Ì“≈—ßÕ¥— ¢Õ߉¡â ≥ ®¥ÿ §≈“°∑Ë’ 0.05% OFFSET (°°./´¡.2) 8.°Ì“≈—ßÕ—¥ª√–≈—¬¢Õ߉¡â (°°./´¡.2) CMax = PMax / A (°°./´¡.2) 9.‚¡¥≈Ÿ  — ¬¥◊ À¬àÿπ E = §«“¡‡§âπ ∑Ë’ P.L. / §«“¡‡§√’¬¥ ∑Ë’ P.L. À¡“¬‡Àμÿ 11.. PP..LL.. ÀÀ¡¡“¬“∂¬÷ß∂÷ßPPRROOPPOERRTTIOIONNAALLLLIMIMITIT 4. Cy 4. ÀC¡y “¬∂Àß÷¡“°¬”∂≈ß÷ —ß°Õ“Ì —¥≈¢ß— ÕÕ¥— ߢ‰Õ¡ßâ ‰≥¡â ≥®¥ÿ ®§¥ÿ ≈§“≈°“°∑’Ë∑0Ë’ .00.055%%OOFFFFSESTET 2. Py À¡“¬∂÷ß ·√ß°¥ ≥ ®ÿ¥§≈“°∑’Ë 0.05 % OFFSET 5. C À¡“¬∂ß÷ °”≈ß— Õ—¥ª√–≈—¬¢Õ߉¡â 23.. PSy À¡“À¬∂¡ß÷ “·¬√∂ß°ß÷ ¥§≥«“®¡¥ÿ ‡§§≈âπ“¢°∑ÕË’ß0‰.¡05â %∑’Ë PO.FLF.SET max 3. S À¡“¬∂÷ß §«“¡‡§âπ¢Õ߉¡â ∑’Ë P.L. 6. E 5. ÀC¡“M¬ax∂À÷ß¡‚“¡¬¥∂≈Ÿ ÷ß— ¬°◊¥Ì“À≈¬—ßàπÿ Õ—¥ª√–≈—¬¢Õ߉¡â 6. E À¡“¬∂÷ß ‚¡¥Ÿ≈— ¬◊¥À¬ÿàπ 1-72 À¡«¥ß“π‚§√ß √“â ß·≈–ª∞æ’«»‘ «°√√¡

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ ‚§√ß°“√ÇÇÇÇÇÇ.ÇÇÇÇÇÇÇÇ. ∫ø.¡∂.(∑) 202.2-2550 ∑–‡∫¬’ π∑¥ Õ∫ÇÇÇÇÇÇÇ  ∂“π∑°Ë’ Õà  √“â ßÇ.ÇÇÇÇÇÇÇ.ÇÇÇ. ºŸâ∑¥ Õ∫ ÇÇÇÇÇÇÇÇÇÇÇÇÇÇ...ÇÇÇ. (Àπ૬ߓπ∑’Ë∑Ì“°“√∑¥ Õ∫) ºŸâμ√«® Õ∫ º√⟠∫— ®“â ßÇÇÇÇÇÇÇÇÇÇÇÇÇÇ.. °“√∑¥ Õ∫À“§à“ Õπÿ¡—μ‘ ºπ⟠“Ì  ßà ÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇ. ™π¥‘ μ«— Õ¬“à ßÇÇ.ÇÇ∑¥ Õ∫§√ßÈ— ∑ÇË’ Ç.Ç ·√ßÕ—¥„π·π«¢π“π‡ ’È¬π¢Õ߉¡â ∑¥ Õ∫«π— ∑ÇË’ ÇÇÇÇÇ.Ç·ºπà ∑ÇË’ ÇÇ. ·√ß°¥ P (°°.) ‰¡Çâ ÇÇÇÇÇÇÇÇ ™π‘¥‰¡âμ—«Õ¬à“ß ‰¡Çâ ÇÇÇÇÇÇÇ.. °“√À¥μ—«¢Õ߉¡â (¡¡.) ‰¡Çâ ÇÇÇÇÇÇÇÇ §«“¡‡§√’¬¥ (STRAIN) 1 ™àÕß = ÇÇÇÇÇ ¡¡. 1 23 §«“¡‡§πâ (STRESS) °°./´¡.2 1 2 3 1 23 PMax (°°.) ¿“æ√Õ¬·μ° ™π‘¥°“√·μ° À¡«¥ß“π‚§√ß √â“ß·≈–ª∞æ’«»‘ «°√√¡ 1-73

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ ¡∂.(∑) 203-2550 ¡“μ√∞“π°“√∑¥ Õ∫À“§“à §«“¡™◊πÈ ¢Õ߉¡â (Moisture Content of Wood) 1. ¢Õ∫¢“à ¬ ¡“μ√∞“π°“√∑¥ Õ∫πȧ’ √Õ∫§≈ÿ¡∂÷ß°“√À“ª√‘¡“≥§«“¡™Èπ◊ ¢Õ߉¡â ‚¥¬«∏‘ Õ’ ∫·Àßâ 2. 𬑠“¡ 2.1 §«“¡™Èπ◊ ¢Õ߉¡â À¡“¬∂ß÷ Õ—μ√“ «à π¢ÕßπÈ”Àπ—°¢Õߧ«“¡™◊πÈ ∑Õ’Ë ¬àŸ„π‡π◊ÈÕ‰¡â μÕà πÈ”Àπ°— ¢Õ߉¡∑â Ë’ Õ∫·Àßâ ®ππ”È Àπ°— §ß∑‚’Ë ¥¬§¥‘ ‡ªìπ√âÕ¬≈– (§à“¢Õߧ«“¡™Èπ◊ ¢Õ߉¡âÕ“®¡“°°«“à 100 °‰Á ¥â) 2.2 §«“¡À¡“¬¢Õߧ”∑„Ë’ ™„â π¡“μ√∞“π°“√∑¥ Õ∫‰¡πâ È’ „À⇪ìπ‰ªμ“¡¡“μ√∞“πº≈‘μ¿—≥±å Õμÿ  “À°√√¡ ¡Õ°.421 ‰¡â·ª√√ªŸ : ¢Õâ °”Àπ¥∑«Ë— ‰ª 3. ™—Èπ§ÿ≥¿“æ·≈– —≠≈°— …≥å „À⇪ìπ‰ªμ“¡¡“μ√∞“πº≈‘μ¿—≥±åÕÿμ “À°√√¡ ¡Õ°. 424 ‰¡â·ª√√Ÿª :  ”À√—∫ß“π °àÕ √â“ß∑Ë—«‰ª 4. «∏‘ ∑’ ” 4.1 ‡§√ËÕ◊ ß¡Õ◊ ·≈–Õÿª°√≥å ª√–°Õ∫¥â«¬ 4.1.1 μÕŸâ ∫‰øø“Ñ (Electric Dry Oven) ‡ªìπμŸâÕ∫∑’Ë “¡“√∂ª√∫— ·≈–§«∫§¡ÿ Õÿ≥À¿¡Ÿ ‰‘ ¥â  ”À√∫— °“√∑¥ Õ∫πÈ’„À⧫∫§ÿ¡∑Ë’Õÿ≥À¿Ÿ¡‘ 103 + 2 Õß»“‡´≈‡´’¬  ‚¥¬μ≈Õ¥„π™à«ß‡«≈“∑Ë’ μâÕß°“√Õ∫‰¡âμ—«Õ¬à“ß ®ππÈ”Àπ—°≈¥≈ߧß∑Ë’ μŸâÕ∫‰øøÑ“§«√¡’Õ“°“»À¡ÿπ‡«’¬π¿“¬„π ‡æ◊ËÕ„ÀÕâ ≥ÿ À¿Ÿ¡‡‘ ∑“à °—π‚¥¬∑«Ë— ·≈–§«√¡™’ àÕß√–∫“¬‰Õπ”È ÕÕ°‰¥¥â ⫬ 4.1.2 ‡§√Ë◊Õß™—ßË „À⡧’ «“¡≈–‡Õ’¬¥¢Õß°“√™Ë—ßπ”È Àπ°— ‰¥â ‰¡πà Õâ ¬°«à“ 0.05 °√—¡ 4.2 °“√‡μ√’¬¡μ«— Õ¬“à ß ‡μ√’¬¡‰¡âμ—«Õ¬à“ß∑’ˉ ‡√’¬∫ (Dressed Timber) ·≈–‡°≈È’¬ß (Clear Wood) ·≈–μâÕ߉¡à ‡§≈◊Õ∫ “√‡§¡’ ¢π“¥ 2.5x2.5x6 ´¡. ™π¥‘ ≈– 3 ∑Õà π 4.3 ·∫∫øÕ√å¡ „™â·∫∫øÕ√å¡∑’Ë ∫ø. ¡∂.(∑) 203.1-2550 : °“√∑¥ Õ∫À“§à“§«“¡™◊πÈ ¢Õ߉¡â 4.4 °“√∑¥ Õ∫ 4.4.1 ¢®—¥‡ ¬’È π‰¡â∑‡Ë’ °“–Õ¬àŸμ“¡º«‘ ¢Õ߉¡âμ«— Õ¬“à ßÕÕ° ·≈–™Ë—ßπ”È Àπ°— ¢Õ߉¡μâ —«Õ¬“à ß ‚¥¬ ¬Õ¡„Àâ§≈“¥‡§≈◊ËÕπ‰¥â + 0.05 °√—¡ πÈ”Àπ—°∑’Ë™—Ë߉¥âπ’È®–‡ªìππÈ”Àπ—°¢Õ߉¡âμ—«Õ¬à“ß°àÕπ Õ∫·Àâß (Original Weight) 1-74 À¡«¥ß“π‚§√ß √“â ß·≈–ª∞æ«’ ‘»«°√√¡

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ 4.4.2 π”‰¡âμ«— Õ¬“à ߇¢“â „πμÕ⟠∫ ‚¥¬„À§â «“¡√Õâ πºà“π‰¥∑â «Ë— ∂ß÷ ∑°ÿ ∑Õà π ∑’ËÕÿ≥À¿Ÿ¡‘ 103 + 2 Õß»“‡´≈‡´’¬  μ√«® Õ∫πÈ”Àπ—°¢Õ߉¡âμ—«Õ¬à“ß∑ÿ°Ê ™à«ß√–¬–‡«≈“ 2 ™—Ë«‚¡ß À√◊Õ ®π°«à“‰¡μâ «— Õ¬à“ß®–·Àâß π‘∑ª√“»®“°§«“¡™Èπ◊ ·≈–¡π’ ”È Àπ—°§ß∑’Ë 4.4.3 π”‰¡μâ —«Õ¬“à ßÕÕ°¡“™Ëß— π”È Àπ°— Õ’°§√—ÈßÀπËß÷ ‚¥¬¬Õ¡„À§â ≈“¥‡§≈◊ËÕπ‰¥‰â ¡à‡°π‘ 0.05 °√—¡ πÈ”Àπ—°∑’™Ë ßË— ‰¥âπ’È ®–‡ªìππ”È Àπ°— ¢Õ߉¡âμ—«Õ¬“à ßÀ≈ß— Õ∫·Àâß (Oven Dry-Weight) 5. °“√§”π«≥ „À⥔‡π‘π°“√§”π«≥μ“¡«∏‘ ’∑’Ë°”À𥉫â„π·∫∫øÕ√¡å μ“¡¢Õâ 4.3 6. °“√√“¬ß“π „À√â “¬ß“πμ“¡·∫∫øÕ√å¡ ∫ø. ¡∂.(∑) 203.1-2550 : °“√∑¥ Õ∫À“§“à §«“¡™◊Èπ¢Õ߉¡â 7. ‡°≥±°å “√μ—¥ ‘π·≈–§«“¡§≈“¥‡§≈◊ËÕπ∑’¬Ë Õ¡„Àâ ‡°≥±å°“√μ—¥ ‘π„À⇪ìπ‰ªμ“¡ ¡∂.104 : ¡“μ√∞“πß“π‰¡â „™â§à“‡©≈’ˬ°“√∑¥ Õ∫À“§à“ §«“¡™È◊π¢Õ߉¡â ·μà≈–™π‘¥ (¢âÕ 5 „π·∫∫øÕ√å¡ ∫ø. ¡∂.(∑) 203.1-2550 : °“√∑¥ Õ∫À“§à“ §«“¡™π◊È ¢Õ߉¡â ) 8. ¢âÕ§«√√–«—ß 8.1 ‰¡âμ«— Õ¬“à ß∑’Ë®–π”¡“∑¥ Õ∫μâÕßÕ¬„àŸ π ¿“æ∑Ë’ ¡∫Ÿ√≥å‡√’¬∫√âÕ¬ ¡¢’ π“¥μ“¡∑°’Ë ”Àπ¥‡∑“à °—πμ≈Õ¥∑ßÈ— ∑àÕπ ·≈–μâÕ߉¡à¡’ μ”Àπ„‘ π‡π◊ÈÕ‰¡â 8.2 °“√Õ∫‰¡μâ «— Õ¬à“ß À“â ¡Õ∫π“π‡°π‘ §«“¡®”‡ªπì ·≈–Àâ“¡‡°‘π°«“à Õÿ≥À¿Ÿ¡∑‘ ’Ë°”À𥉫â (103 + 2 Õß»“‡´≈‡´’¬ ) 9. Àπß—  ◊ÕÕâ“ßÕ‘ß 9.1 ¡“μ√∞“πº≈μ‘ ¿≥— ±åÕÿμ “À°√√¡ ¡Õ°. 421-2525 ‰¡â·ª√√ªŸ : ¢Õâ °”Àπ¥∑—Ë«‰ª 9.2 ¡“μ√∞“πº≈μ‘ ¿≥— ±åÕÿμ “À°√√¡ ¡Õ°. 424-2530 ‰¡·â ª√√Ÿª :  ”À√∫— ß“π°Õà  √â“ß∑«Ë— ‰ª 9.3 FACULTY OF ENGINEERING CHULALONGKORN UNIVERSITY MATERIAL TESTING LABORATORY TEST NO.T 7 MOISTURE CONTENT OF WOOD, REVISED : MAY 1983 9.4 ASTM DESIGNATION : D 2016-74 (REAPPROVED 1983) STANDARD TEST METHODS FOR MOISTURE CONTENT OF WOOD À¡«¥ß“π‚§√ß √“â ß·≈–ª∞æ«’ ‘»«°√√¡ 1-75

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ ‚‚§§√√ßß°°““√√Ç...Ç....Ç....Ç...Ç....Ç....Ç....Ç....Ç.....Ç....Ç....Ç................. ∫∫øø..¡¡∑∂∂.(.(∑∑)) 203.1--22555500 ∑–‡∫’¬π∑¥ Õ∫ÇÇÇÇÇÇ   ∂∂““ππ∑∑’Ë°°’Ë àÕÕà   √√â““â ßßÇ...Ç....Ç...Ç....Ç....Ç....Ç....Ç...Ç....Ç.............. ºŸâ∑¥ Õ∫ Ç....Ç....Ç....Ç...Ç....Ç....Ç....Ç....Ç...Ç....Ç....Ç....Ç...Ç....Ç......Ç.............. (Àπ૬ߓπ∑’Ë∑Ì“°“√∑¥ Õ∫) ºŸâμ√«® Õ∫ ººŸâ√â√Ÿ —∫∫— ®®â““â ßßÇ...Ç....Ç....Ç....Ç...Ç....Ç....Ç....Ç....Ç...Ç....Ç....Ç.............. Õπÿ¡—μ‘ ººŸâπŸâπÌ“”  àßàßÇ....Ç...Ç....Ç....Ç....Ç....Ç.....Ç....Ç....Ç...Ç....Ç....Ç............... °“°√“√∑∑¥¥  ÕÕ∫∫ÀÀ“§à“§««““¡¡™™◊Èπ◊πÈ ¢¢ÕÕ߉ߡ‰â¡â ™™ππ‘¥¥‘ μμ—««— ÕÕ¬¬à““à ßßÇ...Ç....Ç...Ç..∑.¥.∑ ¥Õ ∫Õ§∫√§ß—È√∑—Èß∑Ë.’ ..’ËÇ...Ç............. ∑∑¥¥  ÕÕ∫∫««—π—π∑∑’ËÇ’Ë...Ç....Ç....Ç....Ç.......Ç.....·...º·àπº∑πà ’Ë..∑ÇË’.................. √“¬≈–‡Õ’¬¥ ‰¡âÇÇÇÇÇÇÇ ™π‘¥‰¡âμ—«Õ¬à“ß ‰¡âÇÇÇÇÇÇ ‰¡âÇÇÇÇÇÇÇ 123 123 123 §«“¡¬“« L. (¡¡.) 1.¡‘μ‘¢Õ߉¡âμ—«Õ¬à“ß §«“¡°«â“ß B. (¡¡.) §«“¡Àπ“ T. (¡¡.) 2. π.π.¢Õ߉¡μâ —«Õ¬“à ß°àÕπÕ∫·Àßâ W (°√—¡) (ORIGINAL WEIGHT) 3. π.π.¢Õ߉¡âμ—«Õ¬à“ßÀ≈—ßÕ∫·Àâß WD (°√—¡) (OVEN DRY WEIGHT) 4. ª√‘¡“≥§«“¡™◊È𠇪ìπ√âÕ¬≈– M = (WW--WWDD))x/ 1W00D/xW10D0 5. §à“‡©≈’ˬª√‘¡“≥≥§§««““¡¡™™È◊ππ◊È ‡‡ªªìπìπ√√âÕâÕ¬¬≈≈–– À¡“¬‡Àμÿ: 1-76 À¡«¥ß“π‚§√ß √“â ß·≈–ª∞æ’«»‘ «°√√¡

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ ¡∂.(∑) 204-2550 ¡“μ√∞“π°“√∑¥ Õ∫À“§“à ·√ߥ—¥¢Õ߉¡â (Flexture Test of Wood) 1. ¢Õ∫¢à“¬ ¡“μ√∞“π°“√∑¥ Õ∫π’È §√Õ∫§≈ÿ¡∂÷ß°“√À“§ÿ≥ ¡∫—μ‘∑“ß°≈¢Õ߉¡â¥â«¬·√ߥ—¥ ·≈–¥Ÿ æƒμ‘°√√¡¢Õ߉¡â ‡¡Ë◊Õ∂Ÿ°·√ß°√–∑” μ≈Õ¥ ®π≈—°…≥–°“√·μ°¢Õ߉¡â (Failure) ∑Ë’®ÿ¥«‘∫—μ‘ ·≈«â ·≈–殑 “√≥“À“§“à ∑’ËμÕâ ß°“√ §Õ◊ 1.1 §à“Àπ«à ¬·√ߧ«“¡‡§πâ º‘«πÕ°¢Õ߉¡â ≥ ¢¥’ ªØ¿‘ “§ (Stress in Outer Fiber at Proportional Limit) 1.2 ‚¡¥Ÿ≈— ·μ°√“â « (Modulus of Rupture) 1.3 ‚¡¥Ÿ≈— ¬◊¥À¬πàÿ (Modulus of ElasticIity) 1.4 §“à Àπ«à ¬·√ߧ«“¡‡§âπ Ÿß ÿ¥¢Õß·√߇©Õ◊ π (Maximum Shearing Stress) 1.5 ‚¡¥Ÿ≈— §◊πμ«— (Modulus of Resilience) 1.6 ≈—°…≥–¢Õß°“√«‘∫μ— ‘ (Type of Failure) 2. 𬑠“¡ 2.1 §“à Àπ«à ¬·√ߧ«“¡‡§πâ º«‘ πÕ°¢Õ߉¡â ≥ ¢¥’ ªØ‘¿“§ À¡“¬∂÷ß §“à Àπ૬·√ߧ«“¡‡§πâ ¡“° ∑’Ë ÿ¥∑’Ë°√–∑”∫πº‘«¢Õ߉¡â ·≈–‰¡â “¡“√∂√—∫·√ߧ«“¡‡§âππÈ’‰¥â‚¥¬‰¡à‡°‘¥°“√‡ª≈’ˬπ√Ÿª√à“ß §ßμ—« (Permanent Deformation) 2.2 ‚¡¥≈Ÿ  — ¬◊¥À¬ÿπà À¡“¬∂ß÷ §à“§ÿ≥ ¡∫μ— ∑‘ “ß°≈∑Ë’„™«â —¥æ‘°¥— §«“¡·¢Áß·°√ßà (Stiffness) ¢Õß ‰¡â‡¡◊ËÕ¡’·√ߧ«“¡‡§âπ°√–∑”∑Ë’‰¡πâ È—π 2.3 ‚¡¥Ÿ≈ — ·μ°√“â « À¡“¬∂ß÷ æ‘°—¥¢Õߧà“Àπ૬·√ߥ—¥∑‡’Ë ≈¬¢Õ∫‡¢μ¢Õß ¡¡ÿμ‘∞“π „π°“√ æ ‘ ®Ÿ πå Ÿμ√·√ߥ—¥ 2.4 ‚¡¥≈Ÿ — §π◊ μ—« À¡“¬∂÷ß §à“§≥ÿ  ¡∫μ— ‘∑“ß°≈∑„’Ë ™«â —¥æ‘°¥— §«“¡‡Àπ¬’ « (Toughness) À√Õ◊ æ‘°—¥¢Õß§à“¢’¥§«“¡ “¡“√∂μàÕ°“√μâ“π·√ß°√–·∑° (Shock-Resistance) ¢Õ߉¡â ‡¡Ë◊Õ¡’·√ß §«“¡‡§πâ °√–∑”∑ˉ’ ¡âππ—È 2.5 §“à Àπ૬·√ߧ«“¡‡§âπ Ÿß ¥ÿ ¢Õß·√߇©Õ◊ π À¡“¬∂÷ß §à“§«“¡ “¡“√∂¢Õ߉¡∑â Ë’∑πμàÕ·√ß §«“¡‡§âπ Ÿß ÿ¥ ‚¥¬∑”„Àâ‡πÈ◊Õ‰¡â à«πÀπ÷Ë߇§≈Ë◊Õπμ—«À√◊Õ·¬°À≈ÿ¥ÕÕ°®“°‡π◊ÈÕ‰¡âÕ’° à«π Àπ÷ßË ∑’ËÕ¬àŸμ¥‘ °—π À¡«¥ß“π‚§√ß √â“ß·≈–ª∞æ’«»‘ «°√√¡ 1-77

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ 2.6 πÈ”Àπ°— ª√–≈¬— (Ultimate Load) À¡“¬∂ß÷ πÈ”Àπ—° ßŸ  ¥ÿ ¢Õߧ“à ·√ߧ«“¡‡§πâ ∑’Ë°√–∑” ∫π‰¡â ≥ ®¥ÿ «‘∫μ— ‘ 3. ™—Èπ§ÿ≥¿“æ·≈– —≠≈—°…≥å „À⇪ìπ‰ªμ“¡¡“μ√∞“πº≈‘μ¿—≥±åÕÿμ “À°√√¡ ¡Õ°. 424 ‰¡â·ª√√Ÿª :  ”À√—∫ß“π °àÕ √“â ß∑—Ë«‰ª 4. «‘∏’∑” 4.1 ‡§√ËÕ◊ ß¡Õ◊ ·≈–Õÿª°√≥å ª√–°Õ∫¥â«¬ 4.1.1 ‡§√ÕË◊ ß∑¥ Õ∫‰¡â (Wood Testing Machine) 4.1.2 ‡§√Õ◊Ë ß¡◊Õ«—¥°“√·Õàπμ«— ¢Õ߉¡â 4.2 °“√‡μ√’¬¡μ«— Õ¬à“ß ‡μ√’¬¡‰¡âμ—«Õ¬à“߉ ‡√’¬∫ (Dressed Timber) ·≈–‡°≈È’¬ß (Clear Wood) ¢π“¥ 5x5x90 ´¡.™π‘¥≈– 3 ∑àÕπ‚¥¬‰¡âμ—«Õ¬à“ß∑Ë’®–π”¡“∑¥ Õ∫μâÕß¡’§à“§«“¡™◊Èπ (Moisture Content) Õ¬Ÿà√–À«à“ß√âÕ¬≈– 10 ∂÷ß √âÕ¬≈– 14 4.3 ·∫∫øÕ√å¡ „™â·∫∫øÕ√å¡∑Ë’ ∫ø. ¡∂.(∑) 204.1-2550 : °“√∑¥ Õ∫À“§à“·√ߥ—¥¢Õ߉¡â ∂÷ß 204.4- 2550 : °“√∑¥ Õ∫À“§à“·√ߥ—¥¢Õ߉¡â 4.4 °“√∑¥ Õ∫ 4.4.1 «¥— ¢π“¥·≈–™—ËßπÈ”Àπ—°¢Õ߉¡μâ —«Õ¬à“ß·μà≈–∑Õà π ‡¢’¬π¿“æ “¡¡‘μ¢‘ Õ߉¡âμ—«Õ¬à“߉«â æ√âÕ¡∑—Èß· ¥ß√Õ¬μ”Àπ‘ ∑‘»∑“ß·≈–®”π«π«ßªï∑’ËÀπâ“μ—¥¢Õ߉¡âμ—«Õ¬à“ß ∑ÿ°Ê √–¬– 2.50 ´¡. ‡æ◊ÕË ‡ªìπ¢âÕ¡Ÿ≈°“√æ‘®“√≥“À≈—ß°“√∑¥ Õ∫ 4.4.2 ®—¥μ”·ÀπàߢÕߪ≈“¬∞“π√Õß√∫— „Àâ¡√’ –¬–Àà“ß 70 ´¡. «“߉¡μâ —«Õ¬à“ß„πμ”·Àπßà ∑ºË’ ‘«  —¡º— °—∫‡ âπ«ßªï (Tangertial Surface) À√◊Õº‘«μ“¡·π«‡ È’¬π∑Ë’Õ¬Ÿà„°≈≠≡â (Pith) ∑’Ë ÿ¥ ‚¥¬Àß“¬Àπâ“¢È÷π‡æË◊Õ„À⇧√Ë◊Õß∑¥ Õ∫°¥πÈ”Àπ—°≈ß¡“ À√◊Õ«“߉¡âμ—«Õ¬à“ß„À⺑« μ“¡·π«‡ È’¬π„°≈≠≡â∑Ë’ ÿ¥ ‚¥¬§«Ë”Àπâ“≈߇¡◊ËÕ„™â‡§√Ë◊Õß∑¥ Õ∫¥÷߉¡âμ—«Õ¬à“ߢ÷Èπ ·≈–¬÷¥πÈ”Àπ—°∑Ë°’ ¥‰¡‰â «âÕ¬“à ß¡—Ëπ§ßμ“¡√ªŸ ∑Ë’ 1 1-78 À¡«¥ß“π‚§√ß √â“ß·≈–ª∞æ’«»‘ «°√√¡

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ π”È Àπ°— °¥ L/2 = 35 ´¡. L/2 = 35 ´¡. L = 70 ´¡. √Ÿª∑Ë’ 1 · ¥ß°“√∑¥ Õ∫À“§à“·√ߥ¥— ¢Õ߉¡â 4.4.3 ‡§√◊ËÕß¡Õ◊ «—¥°“√·Õπà μ—«¢Õ߉¡â ·≈–‡§√Õ◊Ë ß∑¥ Õ∫‰¡â∑’Ë®–∑”°“√∑¥ Õ∫„ÀâÕà“π§à“∑Ë’¢¥’ »Ÿπ¬å 4.4.4 °¥π”È Àπ°— μÕà ‡πÕ◊Ë ßÕ¬“à ß™“â Ê ¥«â ¬§«“¡‡√«Á 2.5 ¡¡. μÕà π“∑’ Õ“à π§“à °“√·Õπà μ«— ∑’Ë °÷Ëß°≈“ߢÕ߉¡âμ—«Õ¬à“ß ·≈–πÈ”Àπ—°°¥·μà≈–§√È—ß∑Ë’‡æ‘Ë¡¢÷Èπ‡ªìπ™à«ß‡∑à“Ê °—π ´Ë÷ßÕ¬à“ß πâÕ¬∑’Ë ÿ¥®–μâÕßÕà“π‰¥â 20 §à“ °àÕπ∂÷ß®ÿ¥ª√–≈—¬ (Ultimate) ·≈–„Àâ∫—π∑÷°§à“¢ÕßπÈ” Àπ—°ª√–≈¬— ‰«¥â ⫬ 4.4.5 ∫—π∑÷°≈°— …≥–¢Õß°“√«∫‘ μ— ‘∑Ë’ª√“°Ø∫π‰¡μâ —«Õ¬“à ß À≈ß— ®“°∑°Ë’ ¥π”È Àπ—°®π∂÷ß®¥ÿ ª√–≈—¬·≈«â 4.4.6 ‡¢¬’ π°√“ø· ¥ß§«“¡ ¡— æ—π∏å √–À«à“ßπÈ”Àπ—°°¥∑’ˇæË‘¡¢÷πÈ ·≈–§“à °“√·Õπà μ—« ‚¥¬„Àâ Õ¬„Ÿà π·°πμ—ßÈ ·≈–·°ππÕπμ“¡≈”¥∫— 4.4.7 §”π«≥À“§à“μà“ßÊ ∑Ëμ’ Õâ ß°“√¥ß— · ¥ß‰«„â π·∫∫øÕ√å¡ ∫ø. ¡∂.(∑) 204.2-2550 : °“√∑¥ Õ∫À“§à“·√ߥ¥— ¢Õ߉¡â √Õ¬·μ°‡π◊ÕË ß®“°·√ߥ÷ß (Simple Tension) √Õ¬·μ°·∫∫‡ª√“–¢“¥ (Brash Tension) (¿“楓â π¢â“ß) (¿“楓â π≈à“ß) √Õ¬·μ°¢«“߇ ’¬È π (Cross-Grain Tension) √Õ¬·μ°‡πËÕ◊ ß®“°·√ß°¥ (Compression) (¿“æ¥â“π¢“â ß) (¿“æ¥â“π¢â“ß) √Õ¬·μ°·∫∫øπí ª≈“ (Splintering Tension) √Õ¬·μ°·∫∫©’°μ“¡·π«πÕπ (Horizontal Shear) (¿“楓â π≈à“ß) (¿“楓â π¢â“ß) √ªŸ ∑Ë’ 2 · ¥ßμ—«Õ¬à“ß≈—°…≥–¢Õß°“√«‘∫—μ‘ À¡«¥ß“π‚§√ß √“â ß·≈–ª∞æ«’ »‘ «°√√¡ 1-79

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ 5. °“√§”π«≥ „À⥔‡π‘π°“√§”π«≥μ“¡«‘∏’∑’°Ë ”À𥉫„â π·∫∫øÕ√å¡ ¢âÕ 4.3 6. °“√√“¬ß“π „Àâ√“¬ß“πμ“¡·∫∫øÕ√å¡ „π¢âÕ 4.3 7. ‡°≥±°å “√μ—¥ ‘π·≈–§«“¡§≈“¥‡§≈ÕË◊ π∑¬Ë’ Õ¡„Àâ ‡°≥±å°“√μ—¥ ‘π„À⇪ìπ‰ªμ“¡ ¡∂. 104 : ¡“μ√∞“πß“π‰¡â ‚¥¬„™â§à“‡©≈’ˬ°“√∑¥ Õ∫ À“§“à ·√ߥ¥— ¢Õ߉¡â ·μà≈–™π‘¥ 8. Àπ—ß ◊ÕÕ“â ßÕ‘ß 8.1 ¡“μ√∞“π «. .∑. ¡“μ√∞“π ”À√∫— Õ“§“√‰¡â æ‘¡æå§√È—ß∑Ë’ 5 情¿“§¡ 2526 8.2 ¡“μ√∞“πº≈‘μ¿≥— ±åÕμÿ  “À°√√¡ ¡Õ°. 424-2530 ‰¡â·ª√√Ÿª :  ”À√∫— ß“π°àÕ √“â ß∑—Ë«‰ª 8.3 FACULTY OF ENGINEERING,CHULALONGKORN UNIVERSITY MATERIAL TESTING LABORATORY,: TEST NO.T1 çFLEXURE TEST OF WOOD,é REVISED : MAY 1983 8.4 HARMER E. DAVIS, GEORGE EARL TROXELL AND CLEMENT T. WISKOCIL THE TESTING AND INSPECTION OF ENGINEERING MATERIALS : THIRD EDITION 8.5 FREDERICK F. WANGAARD THE MECHANICAL PROPERTIES OF WOOD 1-80 À¡«¥ß“π‚§√ß √â“ß·≈–ª∞æ’«‘»«°√√¡

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ ‚§√ß°“√.......................................................... ∫∫∫øøø..¡.¡∑∂∂.(.(∑∑))2220044.1.1--2255555000 ∑–‡∫’¬π∑¥ Õ∫ÇÇÇÇÇÇ ‚ §∂√“ßπ°“∑√’Ë°ÇàÕ Ç√“â Çß.Ç.....Ç....Ç....Ç....Ç....Ç....Ç.....Ç....Ç....Ç........ ºŸâ∑¥ Õ∫  ..∂..“..π...∑..’Ë°...àÕ.. ...√..â“..ß..Ç....Ç....Ç....Ç.....Ç....Ç......Ç....Ç....Ç....Ç......... (Àπ૬ߓπ∑’Ë∑Ì“°“√∑¥ Õ∫) ºŸâμ√«® Õ∫ Ǻ√ŸâÇ—∫Ç®“â Çß...Ç....Ç....Ç....Ç....Ç....Ç....Ç.....Ç....Ç....Ç....Ç......Ç......... Õπ¡ÿ μ— ‘ ººŸâ√Ÿâπ—∫”® â“àßß.Ç.....Ç....Ç....Ç....Ç....Ç....Ç.....Ç....Ç......Ç....Ç....Ç....Ç........ °°““√√∑∑¥¥  ÕÕ∫∫ÀÀ““§§à“à“··√√ßߥ¥—¥¥— ¢¢ÕÕß߉¡‰¡â â º™ŸâππÌ“¥‘  μàß«—ÇÕ¬Çà“ßÇ...Ç....Ç....Ç.∑¥Ç ÇÕ∫ǧ√ÇÈ—ß∑ÇË.’ ..Ç....Ç............. ™∑𥑥 μÕ—«∫Õ«¬—πà“∑ß’Ë.Ç....Ç....Ç......Ç......∑...¥... ..Õ·∫º§πà √∑—Èß.Ë’ .∑...’ËÇ....Ç........ ∑¥ Õ∫«—π∑’ËÇÇÇÇ..ÇÇÇ·ºàπ∑’ËÇÇ.. ™π‘¥‰¡âμ—«Õ¬à“ß ·√ß°¥ P (°°.) ‰¡âÇÇÇÇÇÇÇÇ ‰¡âÇÇÇÇÇÇ.. ‰¡âÇÇÇÇÇÇÇÇ °“√·Õàπμ—«¢Õ߉¡â Δ °“√·Õàπμ«— ¢Õ߉¡â Δ °“√·Õπà μ«— ¢Õ߉¡â Δ (¡.¡.) (¡.¡.) (¡.¡.) 1 ™àÕß = ÇÇÇÇÇ ¡.¡. 1 ™Õà ß = ÇÇÇÇÇ ¡.¡. 1 ™àÕß = ÇÇÇÇÇ ¡.¡. 123123123 ·√ß°¥ Ÿß ÿ¥ Pmax (°°.) À¡«¥ß“π‚§√ß √“â ß·≈–ª∞æ«’ ‘»«°√√¡ 1-81

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ ‚‚§§√√ßß°°““√Ç√..Ç....Ç....Ç...Ç....Ç....Ç....Ç....Ç...Ç......Ç....Ç...Ç............... ∫∫ø.¡∑∂∂.(.∑(∑))220044.2-255500 ∑–‡∫’¬π∑¥ Õ∫ÇÇÇÇÇ  ∂“π∑’Ë°Õà  √“â ß...............................................  ∂“π∑’Ë°àÕ √â“ßÇÇÇÇÇÇÇÇ..ÇÇ. (Àπ૬ߓπ∑’Ë∑Ì“°“√∑¥ Õ∫) ºâŸ∑¥ Õ∫ Ç...Ç....Ç....Ç...Ç....Ç....Ç....Ç....Ç...Ç....Ç....Ç....Ç...Ç....Ç......Ç...Ç............ ºâŸμ√«® Õ∫ ººŸâ√√Ÿâ —∫—∫®®â““âßßÇ..Ç....Ç....Ç....Ç...Ç....Ç....Ç....Ç...Ç....Ç......Ç....Ç................ °“°√“∑√∑¥¥  ÕÕ∫∫ÀÀ““§§à“à“··√√ßߥ¥—¥—¥¢¢ÕÕß߉¡‰¡â â Õπ¡ÿ —μ‘ ººŸâπâŸπÌ“”  àßàßÇ...Ç...Ç....Ç....Ç....Ç....Ç...Ç....Ç....Ç....Ç.....Ç....Ç....Ç............ ™™π𑥑¥μμ—«—«ÕÕ¬¬à“ßà“Çß..Ç....Ç.....Ç..∑Ç¥ .∑Õ¥∫ §Õ√∫ßÈ— §∑√’Ë.—Èß..∑..’ËÇ....Ç.......... ∑∑¥¥  ÕÕ∫∫««—ππ— ∑∑’ËÇ.’Ë .Ç....Ç....Ç....Ç.......Ç....Ç.....··ººàππà ∑∑Ç’Ë ’Ë.......Ç............ ™π‘¥‰¡âμ—«Õ¬à“ß √“¬≈–‡Õ’¬¥ ‰¡Çâ ÇÇÇÇ ‰¡âÇÇÇÇÇÇ ‰¡Çâ ÇÇÇÇÇ 12 3 1 2 3 1 2 3 1.¡μ‘ ¢‘ Õ߉¡μâ «— Õ¬“à ß §«“¡°«“â ß b (´¡.) §«“¡≈°÷ d (´¡.) 2.§«“¡¬“«æ°‘ ¥— L (´¡.) 3.π.π.¢Õ߉¡μâ «— Õ¬“à ß W (°√¡— ) 4.§“à Àπ«à ¬·√ߧ«“¡‡§πâ ∑¢Ë’ ¥’ ªØ¿‘ “§(°°./´¡.2) S = (3/2) {(PL) / (bd2)} („™§â “à P ∑¢Ë’ ¥’ ªØ¿‘ “§) 5.‚¡¥≈Ÿ  — ·μ°√“â « (°°./´¡.2) RS = (3/2) {(Pmax L) / (bd2)} 6.‚¡¥≈Ÿ  — ¬¥◊ À¬πàÿ (°°./´¡.2) E = (PL3) / (48 ΔI) („™§â “à P ∑¢Ë’ ¥’ ªØ¿‘ “§) 7.‚¡¥≈Ÿ  — §π◊ μ«— (°°./´¡.2) MR ==SS22/ /1818EE ((„™â S ®“°¢Õâ 4 , E ®“°¢Õâ 6) R 8.§“à Àπ«à ¬·√ߧ«“¡‡§πâ  ßŸ  ¥ÿ ¢Õß·√߇©Õ◊ π Smax = (3/4) (Pmax/ bd) (°°./´¡.2) 9.§“à ß“π‡©≈¬Ë’ ∑πË’ “ÌÈ Àπ°— ª√–≈¬— (°°. - ´¡.) W = Pmax Δ max À¡“¬‡Àμ:ÿ 1-82 À¡«¥ß“π‚§√ß √“â ß·≈–ª∞æ’«‘»«°√√¡

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ ‚‚§§√√ßß°°““√√Ç...Ç....Ç....Ç....Ç....Ç....Ç....Ç....Ç....Ç....Ç....Ç....Ç............ ∫ø∫ø.¡.¡∑∂∂..((∑∑))220044.3.3-2-525050 ∑–‡∫’¬π∑¥ Õ∫ÇÇÇÇÇÇ   ∂∂““ππ∑∑’Ë°°Ë’ àÕÕà   √√â““â ßßÇ...Ç....Ç....Ç....Ç....Ç......Ç....Ç....Ç....Ç........... Ç...Ç....Ç....Ç....Ç....Ç....Ç....Ç....Ç....Ç....Ç....Ç....Ç........Ç....Ç....Ç........... (Àπ૬ߓπ∑’Ë∑Ì“°“√∑¥ Õ∫) ºŸâ∑¥ Õ∫ ººŸâ√Ÿâ√—∫—∫®®â““â ßßÇ...Ç....Ç....Ç....Ç....Ç....Ç....Ç....Ç....Ç........Ç....Ç................ ºâŸμ√«® Õ∫ ºŸâπ” àß............................................................. °“√∑¥ Õ∫À“§à“·√ߥ—¥¢Õ߉¡â ºŸâπÌ“ àßÇÇÇÇÇÇÇÇÇ..ÇÇÇÇ Õπ¡ÿ μ— ‘ ™π¥‘ μ«— Õ¬“à ß............∑¥ Õ∫§√È—ß∑Ë’................... °“√∑¥ Õ∫À“§à“·√ߥ¥— ¢Õ߉¡â ™π‘¥μ—«Õ¬à“ß.ÇÇÇ.Ç..∑¥ Õ∫§√—Èß∑’ËÇ.. ∑¥ Õ∫«π— ∑Ë.’ ..........................·ºàπ∑’Ë................. ™π‘¥‰¡âμ—«Õ¬à“ß ∑¥ Õ∫«—π∑’ËÇÇÇÇÇÇ.Ç.·ºàπ∑Ç’Ë Ç. √“¬≈–‡Õ’¬¥ ‰¡Çâ .ÇÇÇ ‰¡âÇÇÇÇ ‰¡âÇÇÇÇ 1.§“à ‡©≈¬Ë’ ¢ÕßÀπ«à ¬·√ߧ«“¡‡§πâ ∑¢Ë’ ¥’ ªØ¿‘ “§ S (°°./´¡.22) 2.§“à ‡©≈¬Ë’ ¢Õß‚¡¥≈Ÿ  — ·μ°√“â « Rd ((°°°°..//´¡.2) 3.§“à ‡©≈¬Ë’ ¢Õß‚¡¥≈Ÿ  — ¬¥◊ À¬πàÿ E (°(°°./.´/´¡¡.2.)2) 4.§“à ‡©≈¬Ë’ ¢Õß‚¡¥≈Ÿ  — §π◊ μ«— RM (°(°.°/´./´¡¡.2.)2) R 5.§“à ‡©≈¬Ë’ ¢ÕßÀπ«à ¬·√ߧ«“¡‡§πâ  ßŸ  ¥ÿ ¢Õß·√߇©Õ◊ π Smax(°°./´(°¡°.2.)/´¡.2) 6. §“à ‡©≈¬Ë’ ¢Õßß“π‡©≈¬Ë’ ∑πË’ “ÌÈ Àπ°— ª√–≈¬— WAV (°°(.°°-.´-¡´.)¡.) À¡“¬‡Àμ:ÿ À¡«¥ß“π‚§√ß √â“ß·≈–ª∞æ’«‘»«°√√¡ 1-83

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ ‚‚§§√√ßß°°““√√.Ç....Ç....Ç....Ç....Ç....Ç....Ç.....Ç....Ç....Ç....Ç........Ç....Ç............. ∫ø∫ø.¡.¡∑∂∂..((∑∑))22040.4.-42-5255050 ∑–‡∫’¬π∑¥ Õ∫ÇÇÇÇÇ º∑Ÿâ ¥ Õ∫ ............................................................................... (Àπ૬ߓπ∑’Ë∑Ì“°“√∑¥ Õ∫) ºŸâμ√«® Õ∫  ∂“π∑’Ë°àÕ √â“ßÇÇÇÇÇÇÇÇÇÇÇ. Õπ¡ÿ μ— ‘  ∂“π∑’Ë°àÕ √â“ß...................................................... °“√°∑“√¥∑ ¥Õ Õ∫∫ÀÀ““§§“à“à ··√√ßߥ¥¥— ¢—¥Õ¢ßÕ‰¡ßâ ‰¡â ÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇ ............................................................................... º√⟠∫— ®“â ßÇÇÇÇÇÇÇÇÇÇÇÇÇÇ.. º√Ÿâ —∫®“â ß.................................................................. ºπ⟠“Ì  ßà ..ÇÇÇÇÇÇÇÇÇÇÇ..ÇÇ..Ç™π¥‘ μ«— Õ ºŸπâ ” ßà .................................................................... ¬“à ßÇÇÇÇ.Ç.∑¥ Õ∫§√ßÈ— ∑ÇË’ Ç.. ∑™¥π ¥‘ Õμ∫—««Õπ— ¬∑“àÇË’ ß.Ç...Ç....Ç...Ç.∑Ç¥ ..ÕÇ∫.·§º√πà—Èß∑∑ÇË’.Ë’ ...Ç.....Ç................. ∑¥ Õ∫«π— ∑’.Ë ..........................·ºπà ∑’Ë....................... ≈—°…≥–°“√«∫‘ μ— ‘ ™π‘¥¢Õ߉¡âμ—«Õ¬à“ß 123 À¡“¬‡Àμÿ 1-84 À¡«¥ß“π‚§√ß √â“ß·≈–ª∞æ’«‘»«°√√¡

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ ¡∂.(∑) 205-2550 ¡“μ√∞“π°“√∑¥ Õ∫À“§à“°”≈ß— ¥ß÷ ·≈–·√ßμâ“π∑“π°“√·μ°¢Õ߉¡â (Tensile and Cleavage Test of Wood) 1. ¢Õ∫¢“à ¬ ¡“μ√∞“π°“√∑¥ Õ∫π’ȧ√Õ∫§≈ÿ¡∂÷ß°“√À“§ÿ≥ ¡∫—μ‘∑“ß°≈¢Õ߉¡â ‡¡◊ËÕ¡’·√ߥ÷ß„π·π« μÈ—ß©“°°∫— ‡ ¬È’ π ·≈–·√ßμ“â π∑“π°“√·μ°¢Õ߉¡â 2. 𑬓¡ 2.1 °”≈—ߥß÷ ¢Õ߉¡â (Tensile Strength of Wood) À¡“¬∂ß÷ §«“¡ “¡“√∂¢Õ߉¡â∑∑’Ë πμàÕ·√ߥ÷ß  ßŸ  ÿ¥μàÕ·π« μ—Èß©“°°—∫‡ ¬È’ π 2.2 ·√ßμâ“π∑“π¢Õ߉¡â (Cleavage of Wood) À¡“¬∂ß÷ ·√ß∑°Ë’ √–∑”μàÕ°“√μ“â π∑“π°“√·μ°¢Õß ‰¡â ‚¥¬·π«·μ° ®–Õ¬Ÿà„π√–π“∫¢π“π°—∫‡ ’Ȭπ ∑“ߥâ“πμ—Èß©“°°—∫«ßªï (Radial) À√◊Õ∑“ß ¥“â π —¡º— °∫— «ßªï (Tangential) 3. ™Èπ— §ÿ≥¿“æ·≈– ≠— ≈—°…≥å „À⇪ìπ‰ªμ“¡¡“μ√∞“πº≈‘μ¿—≥±åÕÿμ “À°√√¡ ¡Õ°. 424 ‰¡â·ª√√Ÿª :  ”À√—∫ß“π °Õà  √â“ß∑—«Ë ‰ª 4. «∏‘ ∑’ ” 4.1 ‡§√Ë◊Õß¡Õ◊ ·≈–Õÿª°√≥å ª√–°Õ∫¥â«¬ ‡§√Ë◊Õß¡◊Õ ”À√—∫∑¥ Õ∫·√ߥ÷ß ·≈–·√ßμâ“π∑“π°“√·μ°¢Õ߉¡â (Special Devices for Tensile and Cleavage Test) μ“¡√ªŸ ∑Ë’ 1 ‰¡μâ «— Õ¬“à ß ‰¡μâ —«Õ¬“à ß √Ÿª∑’Ë 1 ‡§√ÕË◊ ß¡◊Õ ”À√—∫∑¥ Õ∫°”≈ß— ¥ß÷ ·≈–·√ßμ“â π∑“π°“√·μ°¢Õ߉¡â À¡«¥ß“π‚§√ß √“â ß·≈–ª∞æ«’ »‘ «°√√¡ 1-85

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ 4.2 °“√‡μ√’¬¡μ«— Õ¬à“ß ‡μ√’¬¡‰¡âμ—«Õ¬à“ß∑Ë’‰ ‡√’¬∫ (Dressed Timber) ·≈–‡°≈’È¬ß (Clear Wood) ¢π“¥ 5x5x6 ´¡. ‚¥¬¡’¢π“¥∫√‘‡«≥¢Õß à«π∑’Ë®–∑¥ Õ∫ 2.5x5 ´¡. ™π‘¥≈– 3 ∑àÕπ  ”À√—∫°“√∑¥ Õ∫·√ß ¥÷ß ·≈–¢π“¥ 5x5x9.5 ´¡. ‚¥¬¡’¢π“¥∫√‘‡«≥¢Õß à«π∑Ë’®–∑¥ Õ∫ 5x7.5 ´¡.  ”À√—∫°“√ ∑¥ Õ∫·√ßμâ“π∑“π°“√·μ°¢Õ߉¡â ‰¡âμ—«Õ¬à“ß∑Ë’®–π”¡“∑¥ Õ∫μâÕß¡’§à“§«“¡™È◊π (Moisture Content) Õ¬√àŸ –À«“à ß√Õâ ¬≈– 10 ∂ß÷ √âÕ¬≈– 14 4.3 ·∫∫øÕ√¡å „™â·∫∫øÕ√å¡∑Ë’ ∫ø. ¡∂.(∑) 205.1-2550 : °“√∑¥ Õ∫À“§à“°”≈—ߥ÷ß·≈–·√ßμâ“π∑“π°“√ ·μ°¢Õ߉¡â ·≈– 205.2-2550 : °“√∑¥ Õ∫À“§“à °”≈ß— ¥÷ß·≈–·√ßμâ“π∑“π°“√·μ°¢Õ߉¡â 4.4 °“√∑¥ Õ∫ 4.4.1 «—¥§«“¡°«â“ߢÕ߉¡μâ —«Õ¬“à ß∑®Ë’ –„™â∑¥ Õ∫·√ߥ÷ß ·≈–·√ßμ“â π∑“π°“√·μ°¢Õ߉¡â ‚¥¬„Àâ Õ“à π§“à ‰¥â¡§’ «“¡≈–‡Õ¬’ ¥∂ß÷ 0.1 ´¡. ·≈–™ß—Ë π”È Àπ°— „ÀâÕ“à π§à“‰¥â ¡§’ «“¡≈–‡Õ’¬¥∂÷ß 0.1 °√—¡ 4.4.2 «“߉¡μâ —«Õ¬à“ß„À‡â ¢â“∑’„Ë πμ”·Àπßà ∑Ë’· ¥ß‰«â „π√ªŸ ∑Ë’ 1 „™·â √ߥß÷ Õ¬“à ßμÕà ‡πÕ◊Ë ß¥â«¬§«“¡‡√Á« ª√–¡“≥ 2.5 ¡¡. μÕà π“∑’ ®π∂÷ß®ÿ¥∑‰Ë’ ¡μâ —«Õ¬à“߇√Ë¡‘ ·μ° ∫π— ∑÷°§à“·√ߥß÷  Ÿß ÿ¥∑ÕË’ à“π§à“‰¥â 4.4.3 §“à °”≈ß— ¥ß÷ ¢Õ߉¡â À“‰¥‚â ¥¬π”§“à ¢Õß·√ߥ÷ߠߟ  ¥ÿ ∑Õ’Ë “à π‰¥â À“√¥â«¬æ◊πÈ ∑Ë∫’ √‡‘ «≥ à«π∑’Ë ·§∫∑’Ë ¥ÿ 4.4.4 æ‘®“√≥“À“§“à ¢Õß·√ßμ“â π∑“π°“√·μ°¢Õ߉¡μâ àÕ‡´π쇑 ¡μ√ ¢Õߧ«“¡°«â“ߢÕ߉¡â μ«— Õ¬“à ß 5. °“√§”π«≥ „À⥔‡ππ‘ °“√§”π«≥μ“¡«‘∏’∑Ë°’ ”À𥉫„â π·∫∫øÕ√¡å μ“¡¢âÕ 4.3 6. °“√√“¬ß“π „Àâ√“¬ß“πμ“¡·∫∫øÕ√¡å „π¢Õâ 4.3 7. ‡°≥±°å “√μ—¥ π‘ ·≈–§«“¡§≈“¥‡§≈Ë◊Õπ∑¬Ë’ Õ¡„Àâ ‡°≥±å°“√μ—¥ ‘π„À⇪ìπ‰ªμ“¡ ¡∂. 104 : ¡“μ√∞“πß“π‰¡â ‚¥¬„™â§à“‡©≈Ë’¬°“√∑¥ Õ∫·√ß ¥÷ß ·≈–·√ßμ“â π∑“π°“√·μ°¢Õ߉¡â ·μà≈–™π¥‘ μ“¡·∫∫øÕ√¡å „π¢Õâ 4.3 8. ¢âÕ§«√√–«—ß 8.1 ‰¡μâ —«Õ¬“à ß∑’®Ë –π”¡“∑¥ Õ∫μâÕßÕ¬„Ÿà π ¿“æ∑ ’Ë ¡∫Ÿ√≥å‡√’¬∫√âÕ¬ ¡¢’ π“¥μ“¡∑’°Ë ”Àπ¥‡∑“à °π— μ≈Õ¥∑—Èß∑Õà π ·≈–μâÕ߉¡à¡’μ”Àπ„‘ π‡πÈÕ◊ ‰¡â 8.2 „π°“√∑¥ Õ∫„À⫓߉¡μâ «— Õ¬à“ß„πμ”·Àπßà ∑Ë∂’ °Ÿ μâÕß·≈–¡Ëπ— §ß 9. Àπ—ß ◊ÕÕ“â ßÕß‘ 9.1 ¡“μ√∞“π«»‘ «°√√¡ ∂“π·Ààߪ√–‡∑»‰∑¬ ¡“μ√∞“π ”À√—∫Õ“§“√‰¡â æ‘¡æå§√Èß— ∑’Ë 5 æ.». 2526 9.2 ¡“μ√∞“πº≈‘μ¿—≥±åÕÿμ “À°√√¡ ¡Õ°. 424-2530 ‰¡â·ª√√Ÿª :  ”À√—∫ß“π°àÕ √“â ß∑Ë«— ‰ª 9.3 FACULTY OF ENGINEERING CHULALONGKORN UNIVERSITY MATERIAL TESTING LABORATORY TEST NO.T 5 TENSILE AND CLEAVAGE TEST OF WOOD 9.4 ASTM DESIGNATION : D 143-83 STANDARD METHODS OF TESTING SMALL CLEAR SPECIMENS OF TIMBER. 1-86 À¡«¥ß“π‚§√ß √“â ß·≈–ª∞æ«’ »‘ «°√√¡

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ ‚§√ß°“√ÇÇÇÇÇÇÇÇÇÇÇÇÇ.... ∫∫øø.¡. ∑¡∂.(∑) 220055..11--22555500 ∑–‡∫’¬π∑¥ Õ∫ÇÇÇÇÇ ‚§√ß°“√.......................................................... ºŸ∑â ¥ Õ∫  ∂“π∑’Ë°àÕ √â“ßÇÇÇÇÇÇÇÇÇÇÇ (Àπ૬ߓπ∑’Ë∑Ì“°“√∑¥ Õ∫) ºâŸμ√«® Õ∫  ∂“π∑Ë’°Õà  √â“ß............................................... °“√∑¥ Õ∫À“§à“ Õπÿ¡μ— ‘ Ç..Ç....Ç.....Ç....Ç....Ç....Ç....Ç....Ç....Ç.....Ç....Ç....Ç....Ç....Ç....Ç.....Ç....Ç... ººŸâ√—∫Ÿ√â —∫®®â““âßßÇ...Ç....Ç....Ç.....Ç....Ç....Ç....Ç....Ç....Ç.....Ç....Ç....Ç....Ç....... °Ì“≈—ߥ÷ß·≈–·√ßμâ“π∑“π°“√·μ°¢Õ߉¡â ººŸâπâπŸÌ“”  àßàßÇ...Ç....Ç....Ç.....Ç....Ç....Ç....Ç....Ç....Ç.....Ç....Ç....Ç....Ç....Ç.... ™™ππ‘¥¥‘μμ—««— ÕÕ¬¬à““à ßß..Ç....Ç....Ç...∑ǥǠÕ∑∫¥§ √Èß—Õ∑∫.Ë’ §...√..—Èß..∑...’ËÇ........ ∑∑¥¥  ÕÕ∫∫««—ππ— ∑∑’ËÇ’.Ë ...Ç....Ç....Ç....Ç....Ç....Ç...·Çºπà.·∑º.Ë’ .àπ...∑...’ËÇ.......... °“√°∑“¥√∑ ¥Õ ∫ÕÀ∫“°§Ì“à“≈°—ß”¥≈÷ßß—¢¥Õß÷ ‰¢¡Õâ ß(T‰¡ENâ (STIeOnNsioTEnSTTe)st) ™π‘¥‰¡âμ—«Õ¬à“ß √“¬≈–‡Õ’¬¥ ‰¡âÇÇÇÇÇÇÇÇÇÇ ‰¡âÇÇÇÇÇÇÇÇÇÇ ‰¡Çâ ÇÇÇÇÇÇÇ 1 2 3 1 2 3 1 23 1.¡μ‘ ¢‘ Õ߉¡μâ «— Õ¬“à ß §«“¡¬“« a (´¡.) §«“¡°«“â ß b (´¡.) 2.§«“¡≈°÷ ¢Õ߉¡μâ «— Õ¬“à ß d (´¡.) 3.π.π.¢Õ߉¡μâ «— Õ¬“à ß w (°.) 4.§«“¡™πÈ◊ ¢Õ߉¡μâ «— Õ¬“à ß (√âÕ¬≈–) 5.æπÈ◊ ∑ÀË’ π“â μ¥— ∑„Ë’ ™∑â ¥ Õ∫ , A = a x b (´¡.2) 6.§“à ·√ߥß÷  ßŸ  ¥ÿ , P (°°.) 7.§“à °“Ì ≈ß— ¥ß÷ ¢Õ߉¡â , δ = P / A (°°./´¡.2) 8. §“à ‡©≈¬Ë’ °“Ì ≈ß— ¥ß÷ ¢Õ߉¡â , δAV (°°./´¡.2) d a b À¡«¥ß“π‚§√ß √â“ß·≈–ª∞æ«’ »‘ «°√√¡ 1-87

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°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ ¡∂.(∑) 206-2550 ¡“μ√∞“π°“√∑¥ Õ∫À“§“à ·√߇©◊Õπ¢π“π‡ ¬È’ π¢Õ߉¡â (Shear Test of Wood Parallel to Grain) 1. ¢Õ∫¢“à ¬ ¡“μ√∞“π°“√∑¥ Õ∫πÈ’§√Õ∫§≈ÿ¡∂÷ß°“√À“§à“§«“¡ “¡“√∂„π°“√√—∫·√߇©◊Õπ¢Õ߉¡â„π ·π«¢π“π‡ ’È¬π 2. 𬑠“¡ §«“¡ “¡“√∂„π°“√√—∫·√߇©◊Õπ¢Õ߉¡â À¡“¬∂÷ß §«“¡ “¡“√∂¢Õ߉¡â„π°“√μâ“π∑“π ·√߇§âπ ∑Ë’®–∑”„Àâ à«π¢ÕßÀπâ“μ¥— ‰¡∑â ËÕ’ ¬„àŸ π√–π“∫‡¥¬’ «°—∫·π«·√߇≈Ë◊ÕπÕÕ°®“°°—π 3. ™—πÈ §≥ÿ ¿“æ·≈– ≠— ≈—°…≥å „À⇪ìπ‰ªμ“¡¡“μ√∞“πº≈‘μ¿—≥±åÕÿμ “À°√√¡ ¡Õ°. 424 ‰¡â·ª√√Ÿª :  ”À√—∫ß“π°àÕ √â“ß ∑—«Ë ‰ª 4. «‘∏’∑” 4.1 ‡§√ÕË◊ ß¡Õ◊ ·≈–Õÿª°√≥å ª√–°Õ∫¥«â ¬ 4.1.1 ‡§√Õ◊Ë ß¡◊Õ∑¥ Õ∫·√߇©◊Õπ ∑Ë¡’ ≈’ °— …≥–‡™πà ‡¥’¬«°∫— ∑’·Ë  ¥ß„π√Ÿª∑Ë’ 1 ‚¥¬„À¡â ’√–¬– À“à ß√–À«“à ߢÕ∫¥“â π„π¢Õߺ«‘ ∑√Ë’ Õß√∫— °∫— √–π“∫∑®’Ë –‡°‘¥°“√«∫‘ —μ‘¢Õ߉¡â ‡∑“à °∫— 3 ¡.¡. π”È Àπ°— °¥ ·ºàπ‡À≈°Á °¥ ‰¡âμ«— Õ¬à“ß √ªŸ ∑’Ë 1 ‡§√Ë◊Õß¡◊Õ∑¥ Õ∫À“§“à ·√߇©Õ◊ π¢π“π‡ ’¬È π¢Õ߉¡â À¡«¥ß“π‚§√ß √â“ß·≈–ª∞æ’«»‘ «°√√¡ 1-89

°√¡∑“ßÀ≈«ß™π∫∑ °√–∑√«ß§¡π“§¡ 4.2 °“√‡μ√¬’ ¡μ—«Õ¬à“ß 4.2.1 ‡μ√¬’ ¡‰¡μâ «— Õ¬à“ß∑’ˉ ‡√’¬∫ (Dressed Timber) ·≈–‡°≈¬È’ ß (Clear Wood) ¢π“¥ 5x5x6.3 ´¡. ‚¥¬„Àâ¡’æ◊Èπ∑’Ë∑’Ë®–√—∫·√߇©◊Õπ‡¡Ë◊Õ∑”°“√∑¥ Õ∫ ‡∑à“°—∫ 5 x 5 ´¡. ¥—ß · ¥ß„π√ªŸ ∑Ë’ 2 4.2.2 ‰¡âμ«— Õ¬“à ß∑’®Ë –π”¡“∑¥ Õ∫ μÕâ ß¡§’ «“¡™È◊π (Moisture Content) Õ¬Ÿ√à –À«à“ß√Õâ ¬≈– 10 ∂ß÷ √Õâ ¬≈– 14 AA C A = 5 ´¡., B = 5 ´¡. EEE C = 5 ´¡., D = 6.3 ´¡. BB C E = 2 ´¡. C DD √ªŸ ∑Ë’ 2 ‰¡âμ«— Õ¬“à ß 4.3 ·∫∫øÕ√å¡ „™·â ∫∫øÕ√å¡∑’Ë ∫ø. ¡∂.(∑) 206.1-2550 : °“√∑¥ Õ∫À“§“à ·√߇©◊Õπ¢π“π‡ È’¬π¢Õ߉¡â 4.4 °“√∑¥ Õ∫ 4.4.1 ™Ë—ßπ”È Àπ—° ‰¡μâ —«Õ¬à“ß „À≈â –‡Õ¬’ ¥ ∂ß÷ 0.1 °√—¡ 4.4.2 «—¥¢π“¥ ‰¡μâ —«Õ¬à“ß „Àâ≈–‡Õ’¬¥ ∂÷ß 0.1 ¡.¡. 4.4.3 ∫π— ∑÷°≈°— …≥–∑»‘ ∑“ß ¢Õß≈“¬‰¡â («ßªï) ¢Õßæπ◊È ∑’∑Ë ’Ë√—∫·√߇©Õ◊ π«à“Õ¬Ÿ„à π≈°— …≥–μ—ßÈ ©“°°—∫«ßªï (Radial) À√◊Õ —¡º— °—∫«ßªï (Tangential) À√◊ÕÕ¬àŸ√–À«à“ß·π«μÈ—ß©“°·≈– ·π« ¡— º— °—∫«ßªï (Intermediate) 4.4.4 «“߉¡âμ—«Õ¬“à ß≈ß„π‡§√Õ◊Ë ß¡Õ◊ ∑¥ Õ∫„π≈°— …≥–¥ß— μàÕ‰ªπÈ’ 4.4.4.1 ‰¡¡à ’°“√∫¥‘ μ«— ¢Õ߉¡âμ—«Õ¬à“ß ‡¡ÕË◊ ¡’·√ß°√–∑” 4.4.4.2 «“߉¡μâ «— Õ¬“à ß„ÀÕâ ¬à„Ÿ π·π«¥‘ßË 4.4.4.3 æ◊πÈ º‘«≈à“ߢÕ߉¡μâ —«Õ¬à“ß«“ß„À‰â ¥√â –π“∫∫π∑Ë’√Õß√—∫ 4.4.5 §àÕ¬Ê ª√—∫‡§√◊ËÕß¡Õ◊ „À‡â ¢“â ∑Ë’·≈â«∑”°“√∑¥ Õ∫ ‚¥¬„À·â ºπà ‡À≈°Á °¥‡§≈◊ËÕπ∑Ë’¥«â ¬ §«“¡‡√Á«‰¡à¡“°°«à“ 2 ¡.¡. μÕà π“∑’ ®π‰¡μâ —«Õ¬“à ߇°¥‘ °“√«∫‘ μ— ‘ 4.4.6 ∫—π∑°÷ §à“·√ß°√–∑” Ÿß ÿ¥ ·≈–≈—°…≥–°“√«∫‘ —μ¢‘ Õ߉¡μâ «— Õ¬“à ß 1-90 À¡«¥ß“π‚§√ß √â“ß·≈–ª∞æ’«»‘ «°√√¡