Concrete is probably the most extensively used construction material in the world. However, environmental concerns regarding rapid consumption of natural resources and CO2 emission during cement manufacturing process have brought pressure to reduce cement consumption by the use of cement replacement materials (CRMs). The utilization of calcined clay (metakaolin) and silica fume in concrete has ...

The use of Silica Fume (SF) in short period of time had one of the most dramatic impacts on the industry’s ability to routinely and commercially produce SF modified concrete of flowable in nature but yet remain cohesive, which in turn would develop both high early and high later-age strengths including resistant to aggressive environments. This paper features an experimental study on the nature...

The purpose of the present study was to synthesize and characterize nanosilica from alkali-extraction of silica fume under controlled conditions using poly (vinyl alcohol) (PVA) as a dispersing agent. The dissolution efficiency of silica fume was affected by various factors such as concentration of the reagent, reaction time and temperature. A maximum dissolution efficiency of 91% was achieved ...

This study presents an experimental investigation on self-compacting concrete (SCC) with fine aggregate (sand) replacement of a Quarry Dust (QD) (0%, 25%, 50%, 75%, 100%) and addition of mineral admixtures like Fly Ash (FA) and Silica Fume (SF) & chemical admixtures like super plasticizers (SP). After each mix preparation, 45 cubes specimens and 45 cylinders specimens are cast and cured. The sp...

This paper investigates bending and compressive strengths as mechanical characteristics of cement-based repair mortar containing nano-silica (NS) micro-silica (SF) cement replacements particles polyvinyl alcohol (PVA) fibers. The mentioned materials were added to the in three different conditions, including single (just one material), binary (mixture two admixtures), ternary all admixtures) mod...

Fume hoods are one of the most common types of equipment applied to reduce the potential of particle exposure in laboratory environments. A number of previous studies have shown particle release during work with nanomaterials under fume hoods. Here, we assessed laboratory workers' inhalation exposure during synthesis and handling of CuO, TiO2 and ZnO in a fume hood. In addition, we tested the c...

Ultra-High Performance Concrete (UHPC) improves the bearing capacity as well durability of structural concrete. This study aims to investigate constituents UHPC in both phases: aggregate and cementitious materials. The proper ratio mixture was chosen based on combining an gradation quartz sand crushed stone. In addition, compressive strength hardened cement paste investigated achieve optimal si...

Semi-flexible pavement surfacing is a composite pavement that utilizes the porous pavement structure of the flexible bituminous pavement, which is subsequently grouted with appropriate cementitious materials. This study aims to investigate the compressive strength, flexural strength, and workability performance of cementitious grout. The grout mixtures are designed to achieve high strength and ...

This paper presents the results of an experimental research on the workability and compressive strength of self-compacting concrete. The work focused on concrete mixes having water/binder ratios of 0.35 and 0.45, which contained constant total binder contents of 500 kg/m and 400 kg/m, respectively. The concrete mixes contained four different dosages of a superplasticizer based on carboxylic wit...

This paper presents the multivariate linear models for the evaluation of compressive, flexural and splitting tensile strengths, and toughness ratio of high-performance steel fiber reinforced concrete (HPSFRC). In this study, 44 series of concrete mixes with varying silica fume replacement and fiber dosage (Vf = 0.0, 0.5, 1.0 and 1.5%) were considered. Test results indicated that addition of fib...