Mechanical performance evaluation of polyester fiber and SBR latex compound-modified cement concrete road overlay material

• Proposing a new kind of cement concrete road overlay material comprised of polyester fiber and SBR latex.
• The influence of polyester fiber and SBR latex on the mechanical properties was studied.
• The compound effect of polyester fiber and SBR latex on the mechanical properties of FPMC was studied.
• The compound modification mechanism of polyester fiber and SBR latex on the mechanical properties of FPMC was observed.

For the purpose of effectively dealing with the brittleness and inferior dynamics performance of cement concrete overlay in pavement, this paper proposed a new kind of cement concrete road overlay material comprised of polyester fiber and SBR latex, which is called fiber and polymer compound-modified concrete (FPMC). An experimental test procedure including compressive strength, flexural strength, flexural toughness and impact resistance in this article was investigated. The compound modification mechanism of polyester fiber and SBR latex on mechanical properties of FPMC was surveyed by quantitative analysis in a micro-level, incorporating the measurement of chemical bonding water amount, XRD and SEM. The results indicated that the mechanical properties of FPMC were the most optimal at 0.14 vol.% of polyester fiber and at 90 kg/m3 of SBR latex, and there is an obvious compound effect of polyester fiber and SBR latex on the mechanical properties of FPMC correspondingly. The results of microscopic tests obtained showed that SBR latex took no significant effect on cement hydration in the long-term. Besides, continuous SBR latex films formation presented in cement substrate makes it possible to raise toughness and compact degree of interface transition zone (ITZ). Further, SBR latex trigger polyester fiber and cement paste to lead to a tight mutual connection.