加聚丙烯纖維之高性能混凝土在高溫後之強度恢復

Abstract

中文提要: 高性能混凝土之使用愈來愈受重視, 但其火害後之性質卻令人質疑與關注 .因此針對高性能混凝土高溫後之殘留強度及非破壞檢測進行研究. 高性能混凝土承受 高溫時容易爆裂,Mobil Oil Company研究添加聚合物可降低爆裂的發生, 但其恢復強度頗 受質疑. 本文即針對高性能混凝土添加聚合物在不同目標溫度( 攝氏 200,400,600,800 度), 冷卻時受不同冷卻方式( 自然冷卻, 強制冷卻),冷卻後受不同再養護方式 (空氣中 養護, 水中養護) 與不同再養護齡期 (1,7,28,91 天) 對試體殘留強度之影響. 並利用敲 擊回音試驗儀對試體進行非破壞檢測, 建立應力波波速與抗壓強度間之關係. Abstract: The application of high performance concrete (HPC) has become in- creasingly popular. However, many researchers have concerned and question its propertiesafter high temperature. This study is aimed at the investigation of the residual compressive strength and the nondestructive testing behavior of H PC after high temperature. Although research studies showed that HPC will easily be explosive under high temperature, but Mobil Oil Company found that the addition of polypropylene fiber in HPC will reduce this problem. However, many researchers have still concerned about the recovery strength of high per- formance polypropylene fiber concrete (HPPC)after high temperature. This study is devoted to investigate the effects of high temperature ( Celsius degree:200 ,400,600,800 ) on the recovery strength of HPPC. The major experimental param- eters include cooling method (natural cooling,force cooling), re-curing method ( air curing,water curing ), and curing time ( 1,7,28,91 days). In addition, the impact-echo testing machine is used to study the nondestructive testing be havior of HPPC after high temperature. Furthermore, a correlation between the velocity of stress waveand compressive strength is estiblished.