Rheological properties of CEMI type microfine cement slurry with different fineness

Abstract

In geotechnical engineering, rheological properties of CEMI type microfine cement slurries are deficient. In this paper, rheological performance of microfine cementitious slurry is studied systematically under five particle fineness, five water-binder ratios (W/B), and different contents of superplasticizers (SP) (naphthalene-based (N) and polycarboxylate-based (PCE)). Rheological performance included rheological behavior (fluidity and flow time), key parameters (yield stress, plastic viscosity, and hysteresis area), and time dependent viscosity. Their correlations and reasons were discussed. The results showed that rheological parameters did not change significantly when the W/B is greater than 1.5. For MCIV slurry without SP, when the W/B increased from 1.5 to 2.0, yield stress decreased from 2.3 to 1.53 Pa, plastic viscosity decreased from 8 to 4.5 mPa·s, and hysteretic area is reduced from 466.6 to 206.8 Pa/s. The W/B affects rheological parameters significantly compared with the fineness. The critical rheological model transformation condition of MCII slurry was determined when W/B was 1.2 without SP. For MCIII and MCIV grouts with W/B of 1.0, rheological parameters of slurries with 0.3% PCE are close to those with 0.7 % N. Quantitative relationships among rheological parameters and behavior were established, and correlations were determined. Moreover, relationships among apparent viscosity and W/B, fineness and time are established. To ensure grouting effectiveness in applications, a combination of W/B of 1.0–1.5, MCIII or MCIV fineness, 0.3–0.4% PCE or 0.5–0.7 % N is suggested.