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为研究再生骨料级配对再生保温混凝土抗压强度及其离散性的影响规律,对四种不同再生骨料级配配制的混凝土进行抗压强度试验,并计算抗压强度标准差。以骨料级配为变量,分析了再生保温混凝土抗压强度的变化趋势。研究表明:通过人工调配可提高骨料的物理性质以及优化骨料级配。级配调整后不仅可以提高混凝土抗压强度,也可有效降低抗压强度的离散性,标准差在1~3 MPa范围内。当分别增加大粒径(9.5~19 mm)、小粒径(4.75~9.5 mm)再生粗骨料时,虽依照现行普通混凝土规范[《混凝土泵送施工技术规程》(JGJ/T10-2011)]表现为级配不良,但出现了强度分别提高27.3%和14.1%的现象。同一级配下再生保温混凝土抗压强度呈正态分布,级配调整后,再生保温混凝土抗压强度正态分布曲线均值增加。再生骨料级配调整,可为再生保温混凝土的推广应用提供一定的技术手段。
In order to study the influence of recycled aggregate gradation on the compressive strength and dispersion of reclaimed concrete, the compressive strength of four kinds of concrete with different reclaimed aggregates was tested and the standard deviation of compressive strength was calculated. With aggregate gradation as a variable, the changing trend of compressive strength of recycled concrete was analyzed. The research shows that the physical properties of aggregates can be improved and the aggregate gradation can be optimized by manual blending. Grading adjustment not only can improve the compressive strength of concrete, compressive strength can also effectively reduce the dispersion, the standard deviation of 1 ~ 3 MPa range. When increasing the coarse grain size (9.5-19 mm) and the coarse grain size (4.75-9.5 mm), respectively, according to the current normal concrete specification [Technical Specification for Concrete Pumping Construction (JGJ / T10-2011) ] Showed poor grading, but the phenomenon of increasing the intensity by 27.3% and 14.1% respectively appeared. The compressive strength of recycled concrete under the same level is normal, and the average value of normal distribution curve of compressive strength of recycled concrete is increased after gradation adjustment. Recycled aggregate gradation adjustment can provide certain technical means for the popularization and application of recycled concrete.