基于加速碳化的可循环超高性能混凝土制备研究

Research on the preparation of recyclable ultra-high performance concrete based on accelerated carbonization

提出了一种基于加速碳化的可循环超高性能混凝土(UHPC)制备方法。对强度达到120 MPa的UHPC砂浆试块进行破碎筛分得到再生UHPC骨料(C120R);并利用碳化改性对其增强得到碳化再生UHPC骨料(C120C);通过最紧密堆积原理将C120R和C120C纳入UHPC设计体系,探究加速碳化对C120R性能的影响以及C120R和C120C对UHPC各项性能的影响。结果表明,加速碳化处理可明显优化C120R的压碎值,改善其表面力学性能;而利用C120C制备的UHPC的流动性降低,抗冲击性能基本稳定,抗压强度与体积稳定性略有下降。此外,加速碳化处理可以优化UHPC的孔结构。

This study proposes a preparation method for recyclable ultra-high performance concrete(UHPC)based on accelerated carbonization.Firstly,recycled UHPC aggregates(C120R)were obtained by crushing and sieving UHPC mortar specimens with strength of 120 MPa.Then,carbonized recycled UHPC aggregate(C120C)was obtained by using carbonization modification to enhance C120R;On this basis,C120R and C120C were incorporated into the UHPC design system through dense packing theory,thereby exploring the impact of accelerated carbonization on the properties of C120R and the impacts of C120R and C120C on the various properties of UHPC.The results indicate that accelerated carbonization treatment can significantly optimize the crushing value of C120R and improve the surface mechanical property of C120C.The flowability of C120C-UHPC decreases;the impact resistance is basically stable;and the compressive strength and volume stability slightly decrease.In addition,accelerated carbonization treatment can optimize the pore structure of UHPC.