蒸养参数对轻质管片混凝土力学性能的影响

Effect of Steam Curing Regime on Mechanical Properties of Lightweight Segment Concrete

为了明确基于高钛重矿渣轻骨料制备的盾构隧道轻质管片混凝土的蒸养工艺,通过抗压强度、抗折强度、劈裂抗拉强度和弹性模量试验,研究了静养时间、恒温温度和恒温时间等蒸养工艺参数对轻质管片混凝土力学性能的影响。结果表明:随静养时间由2 h延长至5 h,轻质管片混凝土的抗压强度、抗折强度、劈裂抗拉强度和弹性模量均明显增大;随恒温温度由40℃升高至70℃或恒温时间由4 h延长至16 h,轻质管片混凝土的抗压强度、抗折强度、劈裂抗拉强度和弹性模量均先增高后降低,在恒温温度60℃和恒温时间12 h时各性能指标达到最佳;预湿高钛重矿渣轻骨料的内养护效应可以改善蒸汽养护对混凝土造成的热损伤。

To optimize the curing regime of lightweight segment concrete,which is used for shield tunnel and prepared with titanium-rich slag lightweight aggregate,this work studies the effects of steam curing parameters including rest time,constant temperature and holding time on the compressive strength,flexural strength,splitting tensile strength and elastic modulus of lightweight concrete segments.The results show that the mechanical properties of lightweight segment concrete are gradually enhanced as the rest time extends from 2 h to 5 h,while the mechanical properties of lightweight segment concrete increases first and then decreases with the constant temperature from 40℃to 70℃or the holding time from 4 h to 16 h.The optimal values of compressive strength,flexural strength,splitting tensile strength and elastic modulus are obtained at 60℃and 12 h,respectively.The internal curing of pre-wetted titanium-rich slag lightweight aggregate can reduce the thermal damage of concrete caused by steam curing.