A feasibility study on Engineered cementitious Composites mixed with coarse aggregate

Abstract

Coarse aggregate (CA) is one of the major components in normal cement concrete. However, CA is excluded from the mixture of Engineered Cementitious Composites (ECC), due to its negative effects on material’s tensile behavior. This brings some issues to ECC, such as high shrinkage, high production cost, and insufficient greenness. In an attempt to improve ECC without losing its advantages in tensile properties, the authors challenged to develop ECC with a high volume fraction of CA. In the present study, the authors experimentally studied the influences of CA content and water to binder (w/b) ratio on mechanical properties, shrinkage, and material sustainability. The test results indicated that ECCs mixed with moderate CA not only maintain strong strain-hardening and multiple-cracking characteristics, but also have similar tensile stress and tensile strain capacity, as compared with the conventional ECC. The maximum value of strain capacity of CA-ECC reached 7.9 % at 0.21w/b, and the average tensile strain of all mixtures exceeded 2 %. Moreover, CA was experimentally verified capable to reduce shrinkage, carbon footprint, energy consumption and producing cost simultaneously. The carbon footprint, energy consumption and cost of CA30-ECC18 were reduced by 33.1 %, 24.4 % and 36.1 %, compared to conventional ECC. The present study preliminarily verified the feasibility of producing ECC with coarse aggregate.