Replacement of Conventional Concrete by Light Weight Concrete

Lightweight concrete (LWC) allows for larger spans, fewer piers, and longer bridge designs due to its lower weight and improved durability. Because superstructures with broader shoulders or additional lanes may be improved without requiring extensive work on the substructure, LWC is a particularly desirable construction material at the moment. The goal of this research was to determine the density (unit weight), splitting tensile strength, and elastic modulus of LWC mixtures under various curing circumstances in order to gain a better knowledge of LWC qualities that are critical for long-lasting and costeffective buildings. The researchers also looked at the relationship between the results of the fast chloride permeability test and the outcomes of other tests and the Werner probe surface resistance test to see if the latter may be used to forecast the permeability of LWC mixtures because it is faster and more convenient. Keywords: Light weight aggregate, pumice, compressive strength, density,

Experimental Study on Mechanical Properties of High Strength Glass Fiber Reinforced 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

A review on the effects of artificial light weight aggregate in concrete

The disposal problem of industrial by-products like fly ash, heavy metal sludge, sewage sludge etc. are increasing day by day. To use by-products in large volume the applications like embankment fill or aggregate replacement material should be considered for sustainable development. This study is focused on properties of artificial light weight aggregate on concrete and the effect of cold bonded light weight aggregate on concrete through partial and complete replacement of coarse aggregates. Artificial Lightweight aggregate can be produced by nodulizing the by-product for example fly ash in a pelletizer with a proportionate quantity of water, cement and further hardened by cold bonding or sintering. Due to the impact of earth quake forces all over the world, the need for light weight structural design is increasing presently, as it reduces mass of the structure. The concrete produced is light weight in nature and has added the benefit of reducing overall cost, especially in transportation and placing etc. it has its own advantages like reduced dead load, and thus economic structures, high sound absorption and good fire resistance. Keywords—Artificial light weight aggregate, cold bonding, Fly ash, Fly ash aggregate, Pelletization, and Sintering.

Reinforcing Mechanisms of Coir Fibers in Light-Weight Aggregate Concrete

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.