冻融与高温损伤对SHCC单轴拉伸性能影响试验研究

Test research of frost damage and thermal damage influence on the direct tension performance of SHCC

应变硬化水泥基复合材料（SHCC）优越的抗拉性能和超强韧性显著改变了传统水泥基材料的脆性特征，在工程应用上有很好的前景。通过试验研究了SHCC试件在0、50、100、150、200、300次冻融循环损伤之后的单轴拉伸性能，结果表明在拉伸强度稍有降低的情况下，材料仍保持了良好的韧性，在300次冻融循环损伤后试件极限拉伸应变仍能达到1．54％，只降低了13．9％。研究了不同砂子种类的SHCC试件在20～200℃（300℃）之间六个不同温度损伤下的单轴拉伸性能。得出石英砂配合比试件在120℃高温损伤下，其韧性降低较大，极限拉伸应变为0．79％，只为常温下的13．9％；普通河砂配合比试件在200℃高温损伤下，其极限拉伸应变仍能达到1％以上。

The superior tension performance and the high ductility of SHCC change significantly the brittleness of traditional concrete, providing good prospects in engineering applications.The direct tension test was carried out on SHCC specimens after six different condi- tions, after which they were totally 0,50,100, 150,200 and 300 freeze-thaw cycles, respectively.It was indicated that the tensile strength of specimens, which were after freeze-thaw cycles, decreased slightly, and the ductility of which remained with little change, the ultimate ten- sile strain still got to 1.54%, decreased only by 13.9%.The direct tension test was also carried out on SHCC specimens with diverse sands after injury by six different temperatures,results show that the ductility of the specimens with quartz sand under 120 ~C decreased heavily, the ultimate tensile strain only got to 0.79%, 13.9% of which under room temperatm＇e ;the ultimate tensile strain of the specimens with river sand under 200 ℃ was still up to 1%.