预湿方式对塑钢纤维轻骨料混凝土工作性及强度的影响

Influence of Pre-wetting Method on the Workability and Strength of Plastic-Steel Fiber Lightweight Aggregate Concrete

引入1.5MPa加压预湿方式,研究常压和加压预湿条件下,粉煤灰陶粒与页岩陶粒这2种轻骨料吸水率对塑钢纤维轻骨料混凝土坍落度经时损失和抗压强度的影响规律.结果表明:粉煤灰陶粒在常压预湿和加压预湿下吸水率相差不大,而页岩陶粒在常压预湿和加压预湿下吸水率差异明显,加压预湿时2种轻骨料混凝土坍落度经时损失均最小;1.5MPa加压预湿塑钢纤维轻骨料混凝土的早期抗压强度较低,而后期抗压强度增长率较大;塑钢纤维轻骨料混凝土中、后期抗压强度与轻骨料预湿方式和吸水率关系不大;相对于轻骨料混凝土的抗压强度,1.5MPa加压预湿的压力值对轻骨料的损伤可以忽略不计.

Adopting 1.5 MPa for pressure pre-wetting,effect of different water absorption rate of fly ash ceramsite and shale ceramsite on the loss of slump and compressive strength of the plastic-steel fiber lightweight aggregate concrete was studied under normal or 1.5 MPapressure for pre-wetting.The results show that the water absorption of fly ash ceramsite is almost no difference under normal or 1.5 MPa pressure,but the water absorption of shale ceramsite is greatly different if pre-wetting is made under 1.5 MPa pressure,the loss of slump is minimum for both concretes the compressive strength is relatively low in early stage of the plastic-steel fiber lightweight aggregate concrete while the growth rate of compressive strength in late stage is higher.The way of pre-wetting and water absorption rate of ceramsite have nothing to do with the middle or late compressive strength of the plastic-steel fiber lightweight aggregate concrete.For compressive strength of lightweight aggregate concrete,the damage from 1.5 MPa pressure on the lightweight aggregate can be neglected.