Mechanical and drying shrinkage properties of structural-graded polystyrene aggregate concrete
Mechanical and drying shrinkage properties of structural-graded polystyrene aggregate concrete
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DOI：
10.1016/j.cemconcomp.2008.01.002
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发表时间：
2008-05-01
影响因子：
10.5
通讯作者：
Nadeem, A.
中科院分区：
文献类型：
--
作者：
Tang, W. C.;Lo, Y.;Nadeem, A.
聚苯乙烯骨料混凝土（PAC）是一种具有良好变形能力的轻质混凝土，但由于其明显的低强度特性，其应用通常局限于非结构用途。目前的研究是通过在控制混凝土中用聚苯乙烯骨料（PA）部分替代粗骨料来开发一类结构级PAC，其混凝土密度范围在1400至2100 kg/m(3)之间。进行了大量的室内试验，本文的重点是表征PAC的强度和长期干燥收缩性能。研究的参数包括PA含量和固化条件。结果表明：随着掺合料中PA含量的增加，PAC的混凝土密度、混凝土强度和弹性模量均降低；从量热试验结果来看，聚苯乙烯骨料早期强度加速的增加是由于聚苯乙烯骨料的低比热容造成的。此外，PAC的长期收缩和膨胀与PA含量和水固化时间密切相关。由于聚苯乙烯骨料的不吸水特性，PAC的可逆收缩率与干燥收缩率比对照混凝土低。(C) 2008 Elsevier Ltd版权所有。
Polystyrene aggregate concrete (PAC) is a lightweight concrete with good deformation capacity, but its application is usually limited to non-structural use because of its apparent low strength properties. The present study is an effort to develop a class of structural grade PAC with a wide range of concrete densities between 1400 and 2100 kg/m(3) through partial replacement of coarse aggregate with polystyrene aggregate (PA) in control concrete. Extensive laboratory tests have been carried out and the focus of this paper is to characterize the strength and long-term drying shrinkage properties of PAC. The parameters studied include PA content and curing conditions. The results show that the concrete density, concrete strength and elastic modulus of PAC decrease with increase of PA content in the mix. From the calorimetric test results, the increase in strength acceleration of PAC at early ages is due to the low specific thermal capacity of polystyrene aggregate. Besides, the long-term shrinkage and swelling of PAC are highly dependent on the PA content and the duration of water curing. Owing to the non-absorbent property of polystyrene aggregate, the ratio of reversible shrinkage to drying shrinkage observed for PAC was lower compared to the control concrete. (C) 2008 Elsevier Ltd. All rights reserved.