The Study on the Whole Stress-Strain Curves of Coral Fly Ash-Slag Alkali-Activated Concrete under Uniaxial Compression

Huailiang Wang; Lang Wang; Lei Li; Baoquan Cheng; Yonggang Zhang; Yuhu Wei

doi:10.3390/ma13194291

The Study on the Whole Stress-Strain Curves of Coral Fly Ash-Slag Alkali-Activated Concrete under Uniaxial Compression

Materials (Basel). 2020 Sep 25;13(19):4291. doi: 10.3390/ma13194291.

Authors

Huailiang Wang^{1

2}, Lang Wang¹, Lei Li³, Baoquan Cheng⁴, Yonggang Zhang⁵, Yuhu Wei⁶

Affiliations

¹ College of Civil Engineering and Architecture, Guangxi University, Nanning 530004, China.
² Key Laboratory of Disaster Prevention and Structural Safety of Ministry of Education, Nanning 530004, China.
³ School of civil engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
⁴ School of Civil Engineering, Central South University, Changsha 410083, China.
⁵ Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China.
⁶ College of Civil Engineering, Anhui Jianzhu University, Hefei 230000, China.

Abstract

This study aimed to research the whole stress-strain curves of coral Fly Ash-Slag Alkali-Activated Concrete (CAAC) in different strength grades. Fly ash-slag alkali-activated concrete was used as cementing materials to produce coral aggregate concrete. A monotonic loading test was conducted on the prismatic specimens to obtain elastic modulus (E_c), Poisson's ratio (μ) and the constitutive relationship of CAAC under uniaxial compression. When the strain of CAAC reached the maximum value, the specimen was split and damaged rapidly. As the strength grade increased, the ratio of residual stress (σ_ri) to peak stress (σ_0i) decreased in the range of 0.17-0.28. The E_c of CAAC increased gradually, and μ increased to the peak value and then decreased. According to the test results, the constitutive equation of CAAC can be expressed by piecewise expression, which can better reflect all the experimental characteristics. It was also found that CAAC has many similar characteristics with coral concrete and lightweight aggregate concrete. To improve the strength and toughness of CAAC, some fibers, such as organic fiber, can be added to expand the application of CAAC in engineering projects.

Keywords: Poisson’s ratio; coral aggregates; elastic modulus; fly ash-slag alkali-activated concrete; monotonic loading method; whole stress–strain curve.

Abstract

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