Title:
High-Volume Fly Ash Engineered Cementitious Composite for Underground and Hydraulic Engineering
Author(s):
Xiaoqin Li, Li Zhang, Wenlu Wen, Shihua Li, and Xu Zhou
Publication:
Materials Journal
Volume:
121
Issue:
1
Appears on pages(s):
55-66
Keywords:
engineered cementitious composite (ECC); high-volume fly ash; impermeability; low drying shrinkage; toughness; workability
DOI:
10.14359/51739200
Date:
1/1/2024
Abstract:
Engineered cementitious composites (ECCs) have excellent toughness and crack-control abilities compared to other cement-based materials, which can be used in underground and hydraulic engineering. Nevertheless, excellent impermeability and workability
and low drying shrinkage are also required. Two groups of ECC
mixture proportions with high fly ash-cement (FA/c) and watercement ratios (w/c) were chosen as baselines, and silica fume
(SF) and a shrinkage-reducing agent (SRA) were introduced to
improve the impermeability, workability, and mechanical behaviors.
The workability laboratory evaluation indexes of ECC were
also discussed. ECC mixture proportions with excellent workability
(pumpability and sprayability), high toughness (ultimate tensile
strain ɛtp over 3.5%), good impermeability (permeability coefficient
K = 1.713 × 10–11 m/s), and low drying shrinkage (drying
shrinkage strain ɛst = 603.6 × 10–6) were finally obtained. Then,
flexural and shear tests were carried out for the material flexural/
shear strength and toughness evaluations, giving the characteristic
material properties for the final ECC mixture proportions.