Optimization of calcium carbonate whisker reinforced cement paste for rheology and fracture properties using response surface methodology

Abstract

Cement paste is generally used as a grouting joint material for concrete structures. A good rheology property guarantees the workability of fresh cement paste, and an excellent fracture toughness that reflects the good crack resistance of hardened cement paste. Calcium carbonate whisker (CW) is an inorganic mineral reinforcing material with excellent micromechanical performance, microcrack resistance and environmentally friendly nature. In this study, the rheological and three-point bending tests were conducted on CW reinforced cement paste (CWRCP) to evaluate workability and mechanical properties. The results showed that the yield stress (τ 0) and plastic viscosity (μ) were increased with addition of CW. This was because of the large specific surface area of CW which consumed free water and reduced lubricity between cement particles; and meanwhile, fibrous CW overlapped into net and prevented the flow of fresh cement paste. The addition of CW increased the fracture toughness (K IC) of cement paste due to its microscopic crack resistance effect. Also, the environmental scanning electron microscopy (ESEM) analysis was performed to study the microstructural characteristics. The response surface methodology (RSM) was used to evaluate the influence of CW content (v cw) and water-cement ratio (w/c) to response parameters. Additionally, multiobjective optimization technique was performed to determine best settings for design variables which satisfied ideal response parameters. Conclusively, the optimal solution of CWRCP is beneficial to acquire ideal response goal and provides the basis for engineering applications.

Crack resistance of fiber‐reinforced asphalt mixtures: Effect of test specimen and test condition

“…Studies on fracture behavior of materials need using suitable laboratory test specimens, and the selection of specimen and test method depends on the material type and manufacturing processes 22–24 . For geomaterials such as rock, cement concrete, or asphalt, disc‐shaped specimens are among the reasonable choices because of the ease of extraction from the cylindrical cores 25–27 …”

Optimization of Grouting Material Mixture Ratio Based on Multi-Objective Optimization and Multi-Attribute Decision-Making

“…Related optimization experimental methods have also been widely developed in other fields [26][27][28][29]. In recent years, the response surface methodology (RSM) has been gradually used in the optimization of grouting materials [30][31][32][33]. Iman and Aires [30] studied the influence of silica fume, ultrafine fly ash, and sand as the three main variables of ultra-high property concrete on flow diameter and compressive strength through RSM.…”