Experimental Investigation on the Influence of Organic Extract from Citrus Sinensis as an Additive in Lime Mortar Preparation

Abstract

In the twentieth century, the restoration process in heritage buildings is carried out using cement mortars. From the ongoing study it is found that this can cause extensive damage to the existing structures. In order to avoid consequences of this cement based mortar in the ancient structures, study of lime based mortar is necessary. Many researches are going on to analyses the various strength properties, reactions and the strength factors of lime mortars for different percentages of additives used. Carbonation, which is a slow process, enhances the hardening of the fresh lime mortar and hence increases in its compatibility. For increase in the carbonation rate, various admixtures are added to the lime mortar. It also increases the mechanical strength, weather-resistance and water resistance compared to common lime mortar. This research aims at studying the physical, mechanical and chemical transformations in fresh state and hardened state properties of lime mortar through experimental investigations and for understanding the influence of use of organic extract from Citrus Sinensis (Orange) in lime mortar. Traditional slaking of calcium rich lime was done for various periods of 1, 5, 15 and 30 days. On slaking, quick lime combines with water to form calcium hydroxide which can be used as binder in a mortar. With carbon dioxide from atmosphere, this calcium hydroxide further carbonates to form calcium carbonate. Slaking improves the surface area of the mix. The slaked lime was mixed in the ratio of 1:3 with aggregate, grinded for 0, 5, 10, 15 min and the addition of 5% organic extract. The fresh state properties were obtained based on consistency, workability, and setting time tests. The mechanical property was evaluated by compressive strength test after 28 days of curing. Chemical property of the specimen was evaluated by XRD and FT-IR. Results reveal an increase in the transformation of calcium hydroxide to calcium carbonate in lime mortar with organic addition, enhancing its strength.