Hydration-Microstructural Evolution and Drying Shrinkage of Portland Cement-Blast Furnace Slag System

Abstract

Using several types of Portland cement and blast furnace slag powder(BFS), relationship between the hydration of BFS blended cement and the microstructural evolution were studied. The rate of consumed calcium hydroxide from BFS hydration do not have the constant value, gradually decreases as hydration progresses. The capillary pore volume of BFS blended cement is larger in lower region of hydration degree, and remarkably decreases as hydration progresses. The amount of drying shrinkage of Portland cement and BFS blended cement mortar can be explained by the volume fraction of C-S-H gel in solid phases, the larger shrinkage of mortar with the lager amount of C-S-H.

Drying shrinkage and microstructure characteristics of mortar incorporating ground granulated blast furnace slag and shrinkage reducing admixture

“…The hydration of GGBFS was found to exhibit a different reaction process compared to those of cement minerals, and thus, the hydration products and microstructure formation are different. A previous study [9] indicated that the drying shrinkage of blast furnace cement is associated with the amount of produced C-S-H gel, meaning that it may vary with cement hydration degree, which could be affected by cement type and curing age. Moreover, the calcium silicate hydrate gel characteristics and pore size distribution have a critical influence on the drying shrinkage [11,12].…”

“…Thus, the use of GGBFS can be a less expensive and eco-friendly solution to the problem of emissions of cement production. There are many studies in the literature [9,10] that have dealt with the hydration evolution, microstructure characteristics, and drying shrinkage of blast furnace cement systems. The hydration of GGBFS was found to exhibit a different reaction process compared to those of cement minerals, and thus, the hydration products and microstructure formation are different.…”

Properties of Fiber-Reinforced Mortars Incorporating Nano-Silica

“…For example, the cumulative shrinkage of the NFRM containing slag and steel, basalt, and hybrid fibers was significantly reduced by 23%, 25%, and 26%, respectively relative to that of the corresponding mortar mixtures made with OPC. Previous studies indicated that the amount of drying shrinkage in cementitious systems containing slag is associated with the amount of calcium silicate hydrate produced, and, thus, it may vary with the degree of cement hydration and densification of the matrix [45][46][47]. Thereby, this trend may be linked to the reactivity of slag and the significant reduction of the cement (clinker) factor in these mixtures, which led to discontinuity of the pore structure without excessive refinement, as reported by Zhang et al [18].…”

The Study on Blast Furnace Slag on Different Conditions as Curing Condition and Blaine Value Ratio Influence Improving Strength Performance

“…According to the previous study [2][3][4], drying shrinkage is the primary cause of cracking in concrete structures. The degree of cement hydration reaction is increased when BFS mixed cement is correlated with the amount of produced C-S-H gel.…”