Research Paper
Experimental study on the influence of internal curing on concrete properties using pre-soaked lightweight aggregates and Super Absorbent Polymer
ACI defines Internal Curing (IC) as a process by which the hydration of cement continues because of the availability of internal water that is not part of the mixing water. The introduction of SAP as a new additive for the production of concrete materials presents a number of new possibilities in respect of water control, i.e., the purposeful water absorption and/or water release in either fresh or hardened concrete. Proper curing of concrete structures is important to ensure they meet their intended performance and durability requirements. In conventional construction, this is achieved through external curing, applied after mixing, placing and finishing. Internal curing (IC) is a very promising technique that can provide additional moisture in concrete for more effective hydration of the cement and reduced self-desiccation. Internal curing implies the introduction of a curing agent into concrete that will provide this additional moisture. Concrete expands and contracts because of change in temperature, freezing and thawing cycle and environmental conditions. During early age hardening of concrete exhibits few cracks due to its chemical nature. The main reason for crack development in paste fraction is the loss of water due to chemical reaction and environment. The crack development due to aggregate was mainly on its chemical composition and physical properties. The crack due to plastic shrinkage could be reduced by adopting an internal curing method. This internal curing agent supply absorbed water to concrete to minimize the crack effect due to plastic shrinkage. Internal curing does not replace conventional surface curing but works with it to make concrete more robust. Internal curing can also help compensate for less than ideal weather conditions and poor conventional curing that is often seen in the real world. In this study, M25 Concrete was used to cast cubes beams and cylinders with the mix design of 1:1.78:2.92 replacing sand with presoaked vermiculite and in other mix replacing cement with SAP. The results of 28 days compressive strength, flexural strength and split tensile strength indicates a higher strength with usage of 0.35% SAP and 5% vermiculite as internal curing agents.
Published by: Vishal Bhawar, Dr. Sanjay Kulkarni, Vishwajeet Kadlag
Author: Vishal Bhawar
Paper ID: V5I3-1407
Paper Status: published
Published: May 17, 2019
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