EFFECT OF PARTIAL REPLACEMENT OF SILICA FUME FOR CEMENT ON THE STRENGTH PARAMETERS OF PARTIALLY CINDER BASED LIGHT WEIGHT AGGREGATE CONCRETE

Over the past few decades, extensive studies were in progress all around the globe in concrete technology in finding sustainable alternative materials that can partially or fully replace OPC along with the requirements like durability and strength aspects. Among all the available alternative materials, the industrial waste exhausts like fly ash, silica fume, GGBS, metakaoline and rice husk ash etc., are found to be quite promising. In the present study, a mix design high strength grade concrete of M60 is produced by using binary blending technique by the utilization of Silica fume(SF) and Metakaoline(MK) as partial replacement by weight of cement at different blended percentages ranging from 0-30% in the increments of 10% along with glass fibers having aspect ratio of 100. The different proportions of glass fibers are added in the volume fraction percentages of 0.5-2% in the increments of 0.5%. The test results of fiber reinforced specimens with different percentages of binary blend are compared with control specimens to study the behavior of FRC properties with various percentages of the blends as partial replacement by weight of cement. The test results concluded that the optimum blended percentage of silica fume and metakaoline is 15% i.e., 7.5%SF+7.5%MK along with SP percentage as 1.5% and glass fiber percentage as 1.5% when compared with the control mix. Further, light weight aggregate i.e., pumice stone is replaced to this mix to coarse aggregate at percentages of 25%,50%,75% and 100% respectively and the compressive strength characteristic along with density of concrete was studied and reported

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Reinforcing Mechanisms of Coir Fibers in Light-Weight Aggregate Concrete

Materials ◽

10.3390/ma14030699 ◽

2021 ◽

Vol 14 (3) ◽

pp. 699

Author(s):

Xiaoxiao Zhang ◽

Leo Pel ◽

Florent Gauvin ◽

David Smeulders

Keyword(s):

Cement Hydration ◽

Natural Fibers ◽

Autogenous Shrinkage ◽

Drying Shrinkage ◽

Hydration Reaction ◽

Light Weight ◽

Limited Information ◽

Aggregate Concrete ◽

Coir Fibers ◽

Light Weight Aggregate

Due to the requirement for developing more sustainable constructions, natural fibers from agricultural wastes, such as coir fibers, have been increasingly used as an alternative in concrete composites. However, the influence of coir fibers on the hydration and shrinkage of cement-based materials is not clear. In addition, limited information about the reinforcing mechanisms of coir fibers in concrete can be found. The goal of this research is to investigate the effects of coir fibers on the hydration reaction, microstructure, shrinkages, and mechanical properties of cement-based light-weight aggregate concrete (LWAC). Treatments on coir fibers, namely Ca(OH)2 and nano-silica impregnation, are applied to further improve LWAC. Results show that leachates from fibers acting as a delayed accelerator promote cement hydration, and entrained water by fibers facilitates cement hydration during the whole process. The drying shrinkage of LWAC is increased by adding fibers, while the autogenous shrinkage decreases. The strength and toughness of LWAC are enhanced with fibers. Finally, three reinforcement mechanisms of coir fibers in cement composites are discussed.

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