摘要
在自然资源日渐枯竭与“碳中和”的双重压力下,探索建筑废料在混凝土工程中的应用有着重大意义。本文将桥梁拆除产生的建筑废料破碎制备再生粗骨料,并以不同取代率替换天然骨料制备再生混凝土。基于自由水灰比理论,结合再生粗骨料特点,优化了配合比设计并对比了不同再生骨料取代率(0%、25%、50%、75%、100%)和SAP掺量(0%、0.3%、0.5%、0.7%)对再生混凝土工作性能、力学性能、干燥收缩特性的影响。结果表明,掺入再生粗骨料会降低再生混凝土的工作性能和力学性能,但仍满足规范要求;再生粗骨料取代率增大导致混凝土的干燥收缩变形也逐渐增大。掺入SAP可有效缓解由于再生粗骨料取代率增大对再生混凝土工作性能、力学性能、干燥收缩的不利影响,SAP应用于再生混凝土中可解决再生粗骨料的原始缺陷造成再生混凝土性能劣化的问题。
Under the dual pressures of increasing depletion of natural resources and carbon neutrality,it is of great significance to explore the application of construction waste in concrete.In this work,construction waste from bridge demolition is crushed to prepare recycled coarse aggregate.The recycled coarse aggregate replaces the natural aggregate in different proportions to prepare recycled concrete.Based on the theory of free water-cement ratio and combined with the characteristics of recycled coarse aggregate,the proportion design was optimized.The working properties,mechanical properties,and drying shrinkage characteristics of recycled concrete were investigated for different recycled aggregate replacement ratios(0%,25%,50%,75%,and 100%)and SAP dosing(0%,0.3%,0.5%,and 0.7%).The results show that the addition of recycled coarse aggregate decreases the workability and mechanical properties of recycled concrete,but still meets the specification requirements.As the replacement ratio of recycled coarse aggregate increases,the drying shrinkage of recycled concrete also increases gradually.SAP can effectively alleviate the adverse effects on the workability,mechanical properties and drying shrinkage of recycled concrete caused by the increase in the replacement ratio of recycled coarse aggregate.The use of SAP solves the problem of deterioration in the properties of recycled concrete caused by original defects in the recycled coarse aggregate.
作者
袁斯雅
Yuan Siya(Jiangxi Communications Investment Group Co.,Ltd.,Ji’an 343700,China)
出处
《青海交通科技》
2023年第6期103-111,共9页
Qinghai Transportation Science and Technology
基金
江西省交通运输科技项目(2023H0013)。
作者简介
袁斯雅(1990-),女,工程师,主要研究方向:道路工程及道路交通安全。
