High-Performance Plain and Fibrous Latex-Modified and Microsilica Concrete Overlays

An extensive laboratory experimental program was conducted to develop high-performance fibrous latex-modified concrete (LMC) and microsilica concrete (MSC) overlay mixtures based on target performance characteristics. The designed LMC and MSC overlay normal weight mixtures have the desired workability, 28-day f(')c and f(r) greater than 41 and 4.5 MPa, respectively, drying shrinkage less than 600 mu epsilon at 90 days, low permeability, and adequate hardened air-void parameters. In comparison, the LMC showed lower shrinkage and permeability values than the MSC. The fibrous LMC and MSC mixtures experienced toughness indices I-30 values in the range of 8.78-16.42 and had lower shrinkage values than identical mixtures without fibers. In addition, the values of residual strength factors reflect the same fact that synthetic and steel fibers were very effective in recovering the load in postcracking range. The entire overlay types showed high bond strengths as a result of the excellent surface preparation using water-jet blasting. The careful implementation of the right procedures of mixing, placing, finishing, and curing significantly assisted in producing crack-free overlay applications with high bond strengths.