Studies on workability, microstructural and hardened strength properties on self-compacted geopolymer concrete subjected to ambient curing.

Due to the enormous increase in the development of infrastructure in a very short span, there is an urge in the need of cement that is commonly used as a binder in the construction industry. This research work carries out the formation of self-compacted geopolymer concrete with the help of alkali activators that are used for curing under ambient curing. Durability, mechanical properties and microstructural analysis of ten different types of mixes of concrete with different combinations of fly ash, micro fly ash and slag were studied in detail. The formed mixes do not have any cement content and superplasticizers when tested are found to attain compressive strength of about 45 MPa at 28 days when compared to the normal concrete.

Effect on mechanical properties of lightweight sustainable concrete with the use of waste coconut shell as replacement for coarse aggregate.

Concrete is one of the most important materials that are used in the construction industry all around the world. A larger part of the capacity in concrete is generally employed by the coarse aggregate. Due to the tremendous use of coarse aggregate in the construction industry, the material is getting degraded. In order to preserve the natural material, we are in search of an alternate material that can be used in concrete instead of the original one. So in this research work, it has been attempted to study the mechanical behaviour of lightweight concrete when we use waste coconut shell as coarse aggregate inside concrete. To improve the strength of the concrete, we also use the sisal fibres in various proportions ranging between 1 and 5% in accordance to the binder weight. After the mechanical property tests such as the compression test, spilt tensile strength, flexural test, modulus of elasticity test, and impact resistant test were conducted, finally it was concluded that there was increment in the compression strength up to 5%, and tensile strength was increased to 17% and elastic modulus to 7% when the fibre content used was 3%. Thus, with the use of these waste materials, it was found that the concrete's strength gets increased and it leads to the formation of sustainable concrete thus reducing the pollution in the environment.