Experimental Study on Water/cement Ratio Impact on the Development of the Elastic Modulus of Concrete Using Seawater and Fresh Water in Nha Trang City, Khanh Hoa Province

In order to identify influence of the water/cement ratio(N/X) on the elastic modulus of concrete, especially when using two types of water namely sea water and fresh water in Nha Trang city for concrete production, some experimental research on the effect of water/cement ratio on the elastic modulus of concrete over time has been conducted empirically to clarify this relation. Research results show that salt content in seawater and the water/cement ratio have a great influence on the development of the elastic modulus of the concrete. Specifically, the elastic modulus of concrete using seawater (CP2 grade) grows very Fast in the first period (from 3 to 14 days), but afterwards tends to go slowly over time compared to the development of the elastic modulus of concrete using running water (CP1 grade). The elastic modulus of the concrete using CP1 grade continuously develops over time without degeneration and with the water/cement ratio(N/X) = 0.45, reaching the highest value E = 29,42x104 daN/cm2