Evaluating the Compressive Strength of Concrete Containing Recycled Aggregate in Different Curing Conditions

Abstract

In construction industry, demolished construction waste is recently used as reprocessed aggregate to produce environmentally friendly concrete which is a good substitute to normal crush due to increased demand of ecological growth and conservation benefits. Though, the properties of recycled aggregate concrete are smallest as compared to concrete produced from natural aggregate and these properties can be enhanced by adding some materials having cementitious properties. Rice husk ash (RHA) is used as partial replacement of cement in recycled aggregate concrete to improve the properties as well as to conserve the natural resources. The elementary purpose of this investigation is to determine the compressive strength of concrete by the replacement of cement with different percentages of rice husk ash such as 0%, 7.5%, 10%, 12.5%, 15%, and 17.5% respectively with different curing conditions. For the experimental program approximate 198 cylinders (18 for rapid curing, 90 for normal water curing and 90 for acid curing) are casted with the mix proportion of 1:2:4 and water to cement ratio of 0.50 whereas curing is done at the ages of 3,7,14,21 and 28 days. Various experiments are performed on fresh and hardened concrete to determine the effects of rice husk ash on recycled aggregate concrete with different curing conditions. Linear regression analysis is carried out to determine the compressive strength of concrete. It is pragmatic from the slump test results that the workability of recycled aggregate concrete is decreased by increasing the quantity of rice husk ash. This reduction in slump is due to high water absorption of recycled aggregates and rice husk ash. Further, the compressive strength of recycled aggregate concrete with normal and acid curing is decreased by increasing the percentages of rice husk ash. It is also observed that at 28- days of normal water curing for mix M1,M2,M3,M4,M5 and M6 the compressive strength is increased by 0.96%, 2.74% 1.45%,4.50%,4.23% and 4.22% respectively as compared to the compressive strength values at 28 days of acid water curing. Therefore, it is concluded that recycled aggregate concrete with 10 to 12% of rice husk ash is suitable for properties of concrete. The acid water curing has negative impacts on hardened properties of concrete as it reduced the compressive strength of concrete as compared to normal water curing.

Effect Of Quarry Dust On Mechanical Properties Of Rice Husk Ash-Based Concrete For Sustainable Environment

“…However, the addition of 10 to 15% rice husk ash allows the recycled aggregate concrete to maintain workability, with slump values of about 50mm. This observation is consistent with the experimental findings and aligns with earlier research on the subject matter [12].…”

“…It produced more C-S -H gel, less portlandite, smaller pores, and higher strength than conventional concrete because the silica in RHA reacted with the Ca 2+ ions and OHmake CSH gel. The optimal option in this situation is a 30% substitution of the RHA value [12]. Concrete's mechanical properties and durability are considerably improved when fine aggregate is replaced with quarry dust [13].…”

“…A summary of a few of these research studies may be found in Table . 1. The novelty of this research lies in its investigation of the mechanical properties of concrete through the replacement of 10% of the binder with rice husk ash (RHA) and the variation of fine aggregate proportions with quarry dust (10%, 20%, 30%, 40%, and 50%).In this research, 10% rice husk ash was used because it gives better strength at this optimal proportion which is recommended by previous research [11], [12], [16]. This investigation adds to the novelty of the research, as the specific combination of RHA and varying proportions of quarry dust has not been extensively studied before.…”

Experimental Investigation of Concrete Characteristics Strength with Partial Replacement of Cement by Hybrid Coffee Husk and Sugarcane Bagasse Ash

“…is paper aimed to use low C3A cement with fly ash, which has suitability on the mechanical properties of concrete. In general, the substitution of concrete ingredients with different recycled waste materials mainly allows the sustainability of the resource and reduces the cost of construction and environmental pollution [19,20].…”