超高性能轻质混凝土的弯曲性能研究

本文主要以漂珠作为轻集料,制备出密度在1700-1950kg/m~3的超高性能轻质混凝土(Ultra High Performance Light-weight Concrete,简称UHPLC),对其进行四点弯曲试验,并根据ASTM C1609标准研究其弯曲性能。研究表明:密度范围在1700~1950kg/m~3的UHPLC,其抗压强度在78.8~114.2MPa;2%体积率钢纤维掺量的UHPLC在开裂后有明显的挠度硬化行为,表现出优异的抗弯性能;根据ASTM C1609测试指标,随着密度的增加,UHPLC的初裂强度、0.5mm挠度下的残余强度、2mm挠度下的残余强度、峰值强度、弯曲韧性均增加;U1900抗压强度、抗弯强度比抗弯强度分别为114.2MPa、22.4MPa、11.7k Pa/kg·m-3,其抗弯性能可达国家标准《活性粉末混凝土》RPC160水平,比抗弯强度超过RPC最高等级RPC180。

Flexural Performance of Ultra high Performance Light-weight Concrete

Ultra high performance light-weight concrete (UHPLC) with density of 1700～1950kg/m3 was developed by using cenospheres as light aggregate.Four-point bending test was carried out to investigate the flexural performance according to ASTM C1609 standard.The results show that compressive strength of UHPLC with densities from 1700kg/m3 to 1950 kg/m3 was from 78.8 MPa to 114.2 MPa.UHPLC with 2％ volume steel fiber had obvious deflection hardening behavior after first cracking,showing excellent flexural resistance.According to ASTM C1609,the residual strength,the residual strength under 0.5mm deflection,the residual strength under 2mm deflection,the peak strength and the flexural toughness of UHPLC increased with the increasing of the density.The compressive strength,the flexural strength and the specific flexural strength of U1900 were 114.2MPa,22.4MPa,11.7kPa/kg · m-3,respectively.The flexural performance of U1900 can be up to the RPC160 level according to national standard of "Reactive powder concrete".Moreover,the specific flexural strength of U 1900 can be up to the highest level RPC 180.