Effect Of Small Percentage Additions Of Superabsorbent Polymer On Mechanical Properties Of Concrete [ READ ]
Kenneth Sequeira, B.H.V . Pai
Internal Curing of Concrete has been a topic which has been gathering much more interest in the last couple of years coinciding with the growing demand of high strength concrete in construction. It is a method of countering a problem which unfortunately gets more severe in high strength concrete owing to a greater cement ratio and a correspondingly lower water cement ratio. To make matters worse the water which gets used up during the desiccation process leaves behind empty pores which lead to shrinkage stresses which prevents concrete from achieving its maximum achievable strength. Also in high strength concrete (HSC) the rate of absorption of water into the concrete microstructure is more than the rate at which water gets absorbed into the concrete matrix. This is a problem which prevents conventional methods of curing of water from being successfully implemented in HSC. Therefore we turn to alternate materials which can absorb, hold and supply water as required which also fulfils the role of aggregate such as lightweight aggregate or superabsorbent polymers. We could also use shrinkage reducing admixtures like polyethylene-glycol. The water molecules present in these materials are pulled out due to pressure created in the concrete matrix as water is used up during the curing process. This is also a useful tool for areas where conventional curing is very difficult such as extreme climatic conditions which can lead to excessive evaporation and freezing. Also it will save water losses in sites which is a growing concern in the business as we move towards a more efficient use of our limited resources
Kenneth Sequeira, B.H.V . Pai
Internal Curing of Concrete has been a topic which has been gathering much more interest in the last couple of years coinciding with the growing demand of high strength concrete in construction. It is a method of countering a problem which unfortunately gets more severe in high strength concrete owing to a greater cement ratio and a correspondingly lower water cement ratio. To make matters worse the water which gets used up during the desiccation process leaves behind empty pores which lead to shrinkage stresses which prevents concrete from achieving its maximum achievable strength. Also in high strength concrete (HSC) the rate of absorption of water into the concrete microstructure is more than the rate at which water gets absorbed into the concrete matrix. This is a problem which prevents conventional methods of curing of water from being successfully implemented in HSC. Therefore we turn to alternate materials which can absorb, hold and supply water as required which also fulfils the role of aggregate such as lightweight aggregate or superabsorbent polymers. We could also use shrinkage reducing admixtures like polyethylene-glycol. The water molecules present in these materials are pulled out due to pressure created in the concrete matrix as water is used up during the curing process. This is also a useful tool for areas where conventional curing is very difficult such as extreme climatic conditions which can lead to excessive evaporation and freezing. Also it will save water losses in sites which is a growing concern in the business as we move towards a more efficient use of our limited resources
