Eliminating the Shrinkage of High Strength Concrete by using Super Absorbent Polymer (SAP)


High Strength Concrete (HSC) is one of the most popular types of concrete used in the world. This type of concrete has a low rapid hydration of cementation materials with low w/cm and the external surrounding environment condition exposed the HSC to high autogenous shrinkage. If this shrinkage is not treated well that well led to cracking, in this case HSC need to convenient curing necessary at the earliest time. This study presents the use of Super Absorbent Polymer (SAP) as internal curing agent to eliminate shrinkage. Two types of shrinkage are tested in this study (Autogenous shrinkage and drying shrinkage). Two groups of concrete mixes(A and B) are studied in this study each group have five types of concrete mixes, four mixes with high and ultra-high compressive strength (RPC, MRPC, HSC and SCC) and the last one with normal compressive strength (NSC). Group A represent concrete mixes without SAP addition and group B for concrete mixes with SAP. SAP was added for all mixes at 0.3% by weight of cement and adding 20ml water for each gram of SAP, specimens with dimensions (40*40*160) mm were used for testing shrinkage for each mix with and without SAP, average values for two specimens was taken as a results. It was found that concrete mixes of group B have lower shrinkage than the shrinkage of concrete mixes in group A at 28 days age with reduction of autogenous shrinkage(AS) of (57%, 35%, 37%, 44.5% and 37.5%) respectively and for drying shrinkage the percentage of reduction was (89.5%, 72%, 82%, 70% and 71%) respectively, addition of SAP to concrete mixes proves to have active effect in reducing the shrinkage of concrete.