Characterization of cement concrete during hydration process has been performed using different methods. The determination of initial water-to-cement ratio is one of the challenging tasks since hydration process determines the microstructure of cement concrete and non-destructive methods with high accuracy are desired. This paper presents the results of the investigation into the stress wave tr...

In the present study, the multivariate adaptive regression splines (MARS) technique is employed to estimate the drying shrinkage of concrete. To this purpose, a very big database (RILEM Data Bank) from different experimental studies is used. Several effective parameters such as the age of onset of shrinkage measurement, age at start of drying, the ratio of the volume of the sample on its drying...

The present paper investigates the influence of stabilization with cement, peat ash, and silica sand on permeability coefficient (kv) of compacted clay, using a novel approach to stabilize the clay with peat ash as a supplementary material of cement in the compacted and stabilized soil. In order to assess the mentioned influence, test specimens of both untreated and stabilized soil have been te...

in this research, 210 concrete cube specimens (15cm) were made replacing 0, 5, 10, 15, 20, 25, 30, 35, 40, 50, and 60 percent of slag powder from isfahan steel mill for cement. the control specimens were made with 350 kg/m3 cement content and the water cement ratio in all specimens was 0.51. the slump value and compressive strength of concrete specimens in 7, 28 and 90 days were obtained and th...

OBJECTIVES Favourable results for collarless polished tapered stems have been reported, and cement creep due to taper slip may be a contributing factor. However, the ideal cement thickness around polished stems remains unknown. We investigated the influence of cement thickness on stem subsidence and cement creep. METHODS We cemented six collarless polished tapered (CPT) stems (two stems each ...

a r t i c l e i n f o A hydration kinetics model for Portland cement is formulated based on thermodynamics of multiphase porous media. The mechanism of cement hydration is discussed based on literature review. The model is then developed considering the effects of chemical composition and fineness of cement, water–cement ratio, curing temperature and applied pressure. The ultimate degree of hyd...

Aim. To investigate (a) variability in powder/liquid proportioning and (b) effect of variability on diametral tensile strength (DTS), in a zinc phosphate cement. Statistical analyses (α = 0.05) were by Student's t-test in the case of powder/liquid ratio and one-way ANOVA and Tukey HSD for pair-wise comparisons of mean DTS. The Null hypotheses were that (a) the powder-liquid mixing ratios would ...

The incorporation of pozzolanic materials in concrete has many beneficial effects to enhance the mechanical properties of concrete. The calcium silicate hydrates in cement matrix of concrete increase by pozzolanic reaction of silicates and calcium hydroxide. The fine pozzolanic particles fill spaces between clinker grains, thereby resulting in a denser cement matrix and interfacial transition z...

H nuclear magnetic resonance (NMR), supported by a measurement of the degree of hydration using X-ray diffraction, has been used to fully characterise the nano-scale porosity and composition of calcium-silicate-hydrate (C-S-H), the active component of cement. The resultant “solid” density and composition are 3 g/cm 68 . 2 = ρ ; (Ca)1.53. (Si0.96,Al0.04)O3.51.(H2O)1.92 for an underwater cured, n...