Rigid pavements located on the coast have a greater risk of submerging sea tides, such as in the areas along Pantai Utara (North Beach) road, Semarang, Central Java. Rigid pavement submerged by water has the potential to endure damage because water is one of the factors that cause damage to the pavement, combined with large and repetitive loads so that the road is damaged faster. Tidal flood occurs when seawater is in the tide which coincides with rain so that it leads flooding of roads, especially in Semarang, with a long duration. The purpose of this study is to obtain the value characteristics of slump and bonding time using additive substances and to obtain the compressive strength of rigid Pavement plan with 33.2 Mpa quality with admixture in normal and saltwater environments for 6 hours and 12 hours against static loads. The making of concrete with additive substances in the form of Plastocrete RT06 and Sikament NN was with a treatment method by soaking it in salty water originated from the port of Tanjung Emas Semarang for 6 hours and 12 hours and it then was left in normal temperature conditions. The results of the concrete testing with additive substances (Plastocrete RT06 plus and Sikament NN) have highly compressive strength at the period of 7 days as indicated by exceeding the compressive strength of the plan and experiencing an insignificant increase at the period of 21 and 28 days. The immersion in salt water for 6 hours and 12 hours at the period of 7 days produces a compressive strength beyond the planned compressive strength and surpasses the immersion with normal water because the salt water contains Chloride which affects the hydration process of cement so that it can increase the initial strength of the concrete with compressive strength value close to 40.22 MPa. At the period of 21 and 28 days with the immersion of salt water for 6 hours and 12 hours, there was a considerable decline of 33.89 MPa and 32.83 MPa respectively because the concrete containing excessive chloride resulted in the poor quality of the compressive strength of the concrete.