Enhanced ductility of a rubber-modified composite
An engineered cementitious composite exhibits enhanced ductility at sub-high temperatures after modification with rubber.
A team from Guangdong University of Technology and the University of South Australia has examined the tensile behavior of rubber-modified, engineered cementitious composite (R-ECC) with coupled thermal-mechanical loading.
Rubber particles were introduced as partial replacements for quartz powder at ratios of 0%, 10%, 20% and 30%, while quasi-static uniaxial tensile tests were conducted at temperatures of 25°C, 70°C, 100°C and 150°C.
The study looked at mass loss, pore structure, cracking behavior and tensile stress-strain responses under real-time elevated temperature conditions.
The researchers say the composite shows the highest ultimate tensile strain at 100°C, despite higher temperatures usually reducing it and initial cracking strength.
The authors say the enhancement is the combination of moderate matrix degradation, fibre softening and improved fibre pull-out behavior.
Microstructural analyses reveals that controlled water loss, increased porosity and gradual deterioration of the interfacial transition zone weaken the matrix sufficiently to promote multiple cracking without causing abrupt failure.
At the same time, polyethylene fibres retain effective bridging capacity, enabling stable strain-hardening behaviour.
