再生混合骨料混凝土的配合比设计与力学性能研究

Proportioning design and mechanical properties of recycled mixed aggregate concrete

基于建筑废弃物不断增多和固体废弃物资源化利用的需求,制备了不同再生砖骨料替代率和水玻璃浸泡处理的再生混合骨料混凝土试件。研究了再生砖骨料替代率和水玻璃浸泡处理对试件抗压强度和劈裂抗拉强度的影响。结果表明,在相同龄期下,试件的抗压强度/劈裂抗拉强度会随着再生砖骨料替代率增加而呈现逐渐减小;浸泡水玻璃试件的抗压强度/劈裂抗拉强度都会高于未浸泡水玻璃的试件,即进行浸泡水玻璃处理有助于提升再生混合骨料混凝土试件的抗压强度和劈裂抗拉强度。经过水玻璃浸泡的试件在再生砖替代率为40%时,仍然能够满足C30混凝土的抗压强度要求;再生砖替代率为20%的经过水玻璃浸泡试件的劈裂抗拉强度仍然要高于未经过水玻璃浸泡的纯再生混凝土试件(A0)。通过三次多项式拟合得到了抗压强度/劈裂抗拉强度与再生砖替代率之间的关系表达式,拟合曲线相关系数的可靠性都较高,可以初步采用关系表达式对再生混合骨料试件的抗压强度/劈裂抗拉强度进行预测。

Based on the increasing number of construction waste and the demand for recycling of solid waste,specimens of recycled mixed aggregate concrete with different replacement rates of recycled brick aggregate and water glass immersion treatment were prepared.The effects of recycled brick aggregate substitution rate and water glass immersion treatment on the compressive strength and splitting tensile strength of specimens were studied.The results show that under the same age,the compressive strength/splitting tensile strength of the specimens will gradually decrease with the increase of the replacement rate of recycled brick aggregate;the compressive strength/splitting tensile strength of the soaked water glass specimens with the same replacement rate of recycled brick aggregate will be higher than that of the specimens without soaked water glass,that is to say,the soaked water glass treatment will help to improve the compressive strength and splitting tensile strength of the recycled mixed aggregate concrete test piece.When the replacement rate of recycled brick is 40%,the compressive strength of C30 concrete can still be met.The splitting tensile strength of 20%recycled brick is still higher than that of pure recycled concrete(A0).The relationship between the compressive strength/splitting tensile strength and the replacement rate of recycled brick is obtained by the cubic polynomial fitting,the reliability of the correlation coefficient of the fitting curve is high.The relationship expression can be used to predict the compressive strength/splitting tensile strength of recycled mixed aggregate.