Quantifying curing and composition effects on compressive and tensile strength of 160-250 MPa RPC
Quantifying curing and composition effects on compressive and tensile strength of 160-250 MPa RPC
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DOI：
10.1016/j.conbuildmat.2019.117987
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发表时间：
2020-04-30
影响因子：
7.4
通讯作者：
Ge, Chao
中科院分区：
文献类型：
--
作者：
Rong, Qin;Hou, Xiaomeng;Ge, Chao
采用普通原材料配制了抗压强度达250 MPa的活性粉末混凝土（RPC），并对其进行了免蒸压养护试验。通过对35种配合比和养护条件的优化，提出了抗压强度为160-250 MPa的活性粉末混凝土的计算公式。结果表明，用河砂代替石英砂可使RPC成本降低10%，但抗压强度降低9- 12%。加入石英粉（0.37水泥重量），抗压强度增加2-4%，但降低流动性。定量分析了养护时间、加热时间和温度对RPC抗压强度的影响。推荐的钢纤维含量为2-3%，以实现高抗压强度。RPC在90 ℃蒸汽中养护3d并加热到300 ℃ 24 h，使RPC的抗压强度增加到250 MPa，与仅用90 ℃蒸汽养护3d相比增加了54%。这主要是由于RPC在高温下发生的“内部高压釜”。与蒸汽养护相比，200-300 ℃加热后，RPC劈拉强度和弯曲拉伸强度提高约10%。经过200-300 ℃的加热后，由于RPC的含水量降低到0.4%，可以防止RPC的火灾引起的剥落。RPC可应用于无防火隔离的室内结构。RPC 250具有更高的强度重量比，在某些应用中可能优于钢。(C)2020爱思唯尔有限公司保留所有权利。
Reactive powder concrete (RPC) with a compressive strength of 250 MPa was developed using ordinary raw materials without autoclaved pressure curing. Base on optimizing 35 mix proportions and curing conditions, a calculation formula for 160-250 MPa compressive strength RPC is proposed. Results showed that replacing quartz sand with river sand reduced RPC cost by 10%, while reducing compressive strength by 9-12%. Adding quartz powder (0.37 cement weight) increased compressive strength by 2-4% but reduced fluidity. The influence of curing time, heating time, and temperature on RPC compressive strength was quantified. The recommended steel fiber content is 2-3% to achieve a high compressive strength. Curing RPC in 90 degrees C steam for 3d and heating to 300 degrees C for 24 h, increased RPC compressive strength to 250 MPa, an increase of 54% compared to curing with 90 degrees C steam for 3d only. This is primarily due to "internal autoclave" occurring in RPC at high temperature. Compared with steam curing, after 200-300 degrees C heat, the increase in RPC split-tensile strength and flexural tensile strength was approximately 10%. After 200-300 degrees C heat, fire-induced spalling in RPC can be prevented because the water content was reduced to 0.4%. RPC can be applied in indoor structures without fire insulation. RPC250 exhibits higher strength to weight ratio and could outperform steel in certain applications. (C) 2020 Elsevier Ltd. All rights reserved.