Factorial Design of Cement Slurries Containing Limestone Powder for Self-Consolidating Slurry-Infiltrated Fiber Concrete

Abstract

This study investigated slurries with high penetrability for production of self-consolidating slurry-infiltrated fiber concrete (SIFCON). Factorial experimental design was adopted to assess the combined effects of 5 independent variables on mini-slump test, plate cohesion meter, induced bleeding test, J-fiber penetration test, and compressive strength at 7 and 28 days. The independent variables investigated were the proportions of limestone powder (LSP) and sand, the dosages of high-range water-reducing admixture [superplasticizer (SP)] and viscosity agent (VA), and water-binder ratio (w/b). A 2-level fractional factorial statistical method was used to model the influence of key parameters on properties affecting the behavior of fresh cement slurry and compressive strength. The models are valid for mixtures with 10-50% LSP as replacement of cement, 0.02-0.06% VA by mass of cement, 0.6-1.2% SP, and 50 to 150% sand (percent mass of binder) and 0.42-0.48 w/b. The influences of LSP, SP, VA, sand, and w/b were characterized and analyzed using polynomial regression, which identifies the primary factors and their interactions on the measured properties. Mathematical polynomials were developed for mini-slump, plate cohesion meter, J-fiber penetration test, induced bleeding, and compressive strength as functions of LSP, SP, VA, sand, and w/b. The estimated results of mini-slump, induced bleeding test, and compressive strength from the derived models are compared with results obtained from earlier proposed models that were developed for cement paste. The proposed response models of the self-consolidating SIFCON offer useful information regarding the mixture optimization to secure a high penetration of slurry with low compressive strength.