Fracture properties of alkali-activated slag and ordinary Portland cement concrete and mortar

被引:102
作者
Ding, Yao [1 ]
Dai, Jian-Guo [1 ]
Shi, Cai-Jun [2 ]
机构
[1] Hong Kong Polytech Univ, Dept Civil & Environm Engn, Hong Kong, Hong Kong, Peoples R China
[2] Hunan Univ, Coll Civil Engn, Changsha, Hunan, Peoples R China
基金
美国国家科学基金会;
关键词
Fracture property; Characteristic length; Alkali-activated slag; Concrete; Mortar; Three-point bending test; INTERFACIAL TRANSITION ZONE; HIGH-STRENGTH CONCRETE; FLY-ASH; MECHANICAL-PROPERTIES; DRYING SHRINKAGE; AGGREGATE; TOUGHNESS; PASTE; HYDRATION; BEHAVIOR;
D O I
10.1016/j.conbuildmat.2017.12.202
中图分类号
TU [建筑科学];
学科分类号
0813 ;
摘要
Three-point bending (TPB) tests were conducted on notched beams to compare the fracture properties of alkali-activated slag (AAS) concrete and ordinary Portland cement (OPC) concrete at three different compressive strength levels (30, 50 and 70 MPa). Parallel comparisons were also conducted between MS mortar (AASM) and OPC mortar (OPCM). Load vs. mid-span deflection (P-delta) curves, load vs. crack mouth opening displacement (P-CMOD) curves and load vs. crack tip opening displacement (P-CTOD) curves of the tested beams were obtained. The fracture energy G(F) and the characteristic length (l(ch)) of the MS and OPC concrete and mortar were calculated and analyzed. It was found that the G(F) of AAS concrete was always higher than that of OPC concrete given the same compressive strength, due to their denser and stronger interfacial transition zones (ITZs). At a compressive strength of 30 MPa, the G(F) of AASM was also larger than its OPC counterparts. However, the G(F) of AASM became lower than that of OPCM when the compressive strengths were 50 and 70 MPa, as more initial micro-cracks were formed in the AASM matrix with strength increase. In addition, the l(ch) values of MS concrete and mortar were all smaller than those of OPC, implying that the formers were more brittle given the same compressive strengths. The elastic modulus of MS concrete and mortar were found to be always lower than those of OPC. Micro-structural observations were carried out to explain the above phenomena. (C) 2017 Elsevier Ltd. All rights reserved.
引用
收藏
页码:310 / 320
页数:11
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