For many concretes and mortars, self-desiccation results in the creation of empty capillary porosity within the cement paste microstructure, accompanied by a decrease in achieved hydration, an increase in internal stresses, and an increased propensity for early age cracking. One solution to this problem for low water-to-cement ratio concretes where external curing is ineffective has been the de...

Determination the optimal mix design plays an important role in order to gain the maximum characteristic strength. This research was conducted as a case study for Manjil tunnel project located in Qazvin-Rasht highway. For this purpose, 18 concrete mix designs were prepared at the study phase of the project with specifications such as conventional water-to-cement ratios of 0.4, 0.5 and 0.6, the ...

Cement board reinforced with basalt fibers were prepared by using polymer compounds, 5% of water-based isocyanate-polyester polyol prepolymer blend was used as a fixed percentage, and the rates fıber 5%, 7.5%, 10%, 12.5%, for each them water/cement ratios (W/C) 1.4, 1, 0.75, 0.4, 0.5 respectively. The sample cured 28 days, mechanical physical properties cement fiberboard greatly improved due to...

Abstract Concrete is made with various industrial byproducts, and to check the effectiveness of concrete constituents waste marble powder, Artificial neural network, Random Forest, Support vector machines, Adaptive neuro-fuzzy inference systems models were created. Six parameters used predict compressive strength: cement, fine coarse aggregate, water-to-cement ratio, curing days. The outcomes d...

nano materials have been widely used in laboratory and industrial scales in order to improve various properties of concrete and concrete mixture. the mainstream practice of the researches in this field is to add metallic nano-particles into the concrete mixture. the present research focuses on adding micro-nano air bubbles (mnab) into water before mixing it with aggregate and cement mixtures. i...

Concrete patch repair has long been used to repair the damaged concrete structures. In cold regions, freeze– thaw cycle is one of the major damage factors. Not only the material itself is damaged by freeze–thaw cycles, but also the adhesive interface, which is regarded as the weakest part of composite system, degrades under freeze–thaw cycles. Air entraining agent has long been used to increase...

In the present study, effect of pozzolanic material (Metakaolin and Silica fume) is studied through compressive and Flexural strength in cement concrete. Metakaolin and silica fume area used as cement replacement materials at 5%, 10% and 15% by mass keeping water–cement ratio as 0.42 Compressive and Flexural strength were observed after 7 and 28 days of curing. Silica fume is a by products resu...

Statement of Purpose: Calcium phosphate cements are prepared by mixing calcium phosphate powder with a liquid component to form a paste that hardens over time via a dissolution-precipitation reaction. Thus, in addition to being osteoconductive and resorbable, these biomaterials have the advantageous property of being injectable. This property can be leveraged for castingbased approaches to scaf...

In order to build green mines, goaf is often filled, supported, and sealed with a high-water material eliminate series of environmental problems safety hazards caused by goaf. this study, ordinary Portland cement, sulphoaluminate alkali-activated cement were used as binders prepare full-tailings materials for filling, various water-to-cement ratios. The compressive strength development consolid...