Pore size distribution modification of OPC paste through inclusion of fly ash and sand

Abstract

This paper presents a study into the modification of pore size distribution of ordinary Portland cement (OPC) paste due to inclusion of fly ash (FA) and sand as determined through mercury intrusion porosimetry. Cement-sand mortar specimens were prepared from two different grades of OPC with water to cement (w/c) ratios of 0 . 2, 0 . 3, 0 . 4, 0 . 5 and 0 . 6 and tested at different curing ages from 1 day to 90 days. Cement-FA paste and mortar specimens were also prepared by incorporating FA at four levels of FA to cement (f/c) ratio (0 . 1, 0 . 2, 0 . 3, 0 . 4) and a control mix along with four w/(c + f) ratios (0 . 25, 0 . 35, 0 . 45 and 0 . 55). These specimens were tested at 7, 28 and 90 days. The relationships involving w/c ratio and age with mean distribution radius (r 0 : 5 ) and coefficient (d ) representing dispersion of pore sizes are presented for both types of OPC-sand mortar. The relationships involving w/(c + f) ratio, f/c ratio and age with r 0 : 5 and d are also presented separately for cement-FA paste and mortar.

Correlation Monitoring of Predicted and Actual Strength in CUSUM Quality Control of Concrete

“…Strength of weakly bonded particulate systems like concrete is governed by weakest link, i.e., porosity and pore sizes [9][10][11][12][13] given by form of equation -1 below.…”

“…P is the porosity and r0.5 is the median pore radius or mean distribution radius. The P and r0.5 are related to W/C, degree of hydration and specific gravity of cement, in addition r0.5 is also related mean particle size of cement [10][11][12][13][14]. The relationship of P, r0.5 with W/C, degree of hydration and cement particle size is complex and not linear.…”

Durability deterioration of concrete under marine environment from material to structure: A critical review

“…The microstructure and pore structure of concrete consists of pores, capillary pores, and gel pores. As one of the crucial properties of cementitious concrete, the pore structure accounts for a certain percentage in cementitious concrete, and it is of considerable significance to the transmission characteristics [81,82]. Specifically, pore structure parameters, consisting of porosity and pore size distribution, are essential constituent parts of microstructure.…”