Research on production, performance and fibre dispersion of PVA engineering cementitious composites

AbstractPolyvinyl alcohol (PVA) fibre is considered as one of the most suitable polymeric fibres to be used as the reinforcement of engineered cementitious composites (ECCs). Research and application have shown that PVA–ECC can significantly counteract the deficiency of ordinary concrete. In the present paper, micromechanics based design theory and fracture mechanics formulation leading to energy and strength criteria to achieve strain hardening and multiple cracking are described. Engineered cementitious composites showing pseudo strain hardening behaviour with over 6% of strain capacity under tension is produced. Uniaxial tensile tests of PVA–ECC are conducted and the results support the validity of the proposed theory. Also viscosity modifying agent plays an important role in the dispersion of the fibres in the matrix. It is shown that a uniform distribution of fibres throughout the bulk of the composite material is crucial to its excellent workability, tight crack width and reduction in the autogenous...