人工砂商品混凝土配合比的试验研究

Test Research on Mix Proportion of Ready-mixed Concrete with Artificial Sand

采用70%人工砂与天然细砂混合改善砂级配,可替代天然中砂配制商品混凝土,所配制出的混凝土抗压强度高于天然中砂混凝土。正交试验法设计掺合料人工砂混凝土的配合比,试配结果表明,人工砂占混合砂70%,粉煤灰、矿粉掺量分别为20%、25%,砂率为45%时,在拌合料中加入YS-2B萘系减水剂1.7%,可解决人工砂混凝土需水量大的问题,新拌混凝土坍落度达到180mm的泵送要求;28d抗压强度为32.4MPa,满足C30混凝土的设计强度,60d抗压强度为37.0MPa,人工砂替代天然砂不影响混凝土后期的抗压强度。

Mixed sand with 70% artificial sand and natural sand can be utilized to improve sand gradation, which can replace natural medium sand to prepare ready-mixed concrete, and the concrete compressive strength may be higher than that with natural medium sand. Based on orthogonal experimental method, the mix proportion of admixture concrete with artificial sand can he designed. The results indicate that when mixed sand containing 70% artificial sand, with 20% fly ash and 25% slag, under the sand ratio of 45%, adding 1.7% YS-2B naphthalene superplasticizer into concrete mixture, the great water demand for concrete with artificial sand can he solved and the slump value of fresh concrete can reach 180ram, which can satisfy the pumping concrete requirement. The 28d compressive strength of concrete is 32.4MPa, which can meet the design strength of C30 concrete, and the 60d compressive strength is 37.0MPa. Artificial sand replacing natural sand may have no effect on late compressive strength of concrete.