Shrinkage Study and Strength Aspects of Concrete with Foundry Sand and Coconut Shell as a Partial Replacement for Coarse and Fine Aggregate

Abstract

The demand for natural aggregates (river sand) is increasing day by day, leading to the destruction of the environment, a burden that will be passed on to young people. Further, wastes from various industries are being dumped in landfills, which poses serious environmental problems. In order to ensure sustainability, both the issues mentioned above can be solved by utilizing industrial waste as aggregate replacement in the concrete construction industry. This research is done to find out the results using two substances viz., waste foundry sand (WFS) and coconut shell (CS) substitute for river sand and coarse aggregate. Many researchers have found the maximum benefits of substituted substances used in cement, which has material consistency. This current observation explores these strong waste properties of waste-infused concrete and cement, which experience shrinkage from drying out. The replacement levels for waste foundry sand were varied, between 10%, 20%, and 30%, and for CS, it was 10% and 20%. The experimental outcomes are evident for the strength, which increases by using WFS, whereas the strength decreases by increasing the CS level. The concrete that experiences shrinkage from drying out is included in the waste material, showing a higher magnitude of drying shrinkage than conventional concrete.

Alteration of Structure and Characteristics of Concrete with Coconut Shell as a Substitution of a Part of Coarse Aggregate

“…CS has a significantly lower strength than natural coarse aggregate and is also a lighter material. Therefore, the use of CS in the technology of heavy concrete will inevitably lead to a decrease in the strength characteristics [ 31 , 32 , 33 , 34 , 35 , 46 , 63 , 64 ].…”

“…The drop in the strength characteristics of concrete with the introduction of more than 5% CS as a replacement for part of the natural coarse aggregate is associated with the characteristics of the CS. CS has a significantly lower strength compared with natural coarse aggregate and is also a lighter material, which, at high shell amounts (more than 10%), leads to a significant decrease in the strength of the concrete [ 31 , 32 , 33 , 34 , 35 , 46 , 63 , 64 ]. This makes it possible to involve almost all cement particles in this process and create additional crystallization centers that increase the adhesion strength of CS particles with the cement–sand matrix of concrete, which is in good agreement with the studies reported in [ 33 , 34 , 63 , 64 ].…”

“…The results obtained in studies [13,39] prove the possibility of Therefore, CS is a natural raw material with a high degree of renewal, which makes it possible to use it in significant volumes without the risk of depleting it. Additionally, the application of CS in the composition or reinforcement of materials is presented in a number of the following works [13,[29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48]. The introduction of CS as a component is studied in detail in [29,30].…”

“…It was established that replacement of up to 50% of the fine aggregate with CS is rational and makes it possible to obtain good quality concretes with low penetrating quality (less than 2.7 × 10 −11 m/s) and water absorption up to 5%. In the studies [ 31 , 32 , 33 , 34 , 35 , 45 ], the authors studied the possibility of using CS as a coarse aggregate in the technology of heavy concrete. For example, in [ 31 ], the authors found that the use of CS in concrete as a coarse aggregate in an amount of 10–20% “has a negative effect on the strength characteristics of concrete” and contributes to an increase in drying shrinkage.…”

“…In the studies [ 31 , 32 , 33 , 34 , 35 , 45 ], the authors studied the possibility of using CS as a coarse aggregate in the technology of heavy concrete. For example, in [ 31 ], the authors found that the use of CS in concrete as a coarse aggregate in an amount of 10–20% “has a negative effect on the strength characteristics of concrete” and contributes to an increase in drying shrinkage. In one study [ 32 ], the authors estimated the strength properties of concrete with partial replacement of coarse aggregate with CS.…”