SUSTAINABLE SELF-CONSOLIDATING CONCRETE MIXTURE DEVELOPMENT FOR USE IN PREFABRICATED CONCRETE NEW JERSEY BARRIERS

ABSTRACT

This paper presents a joint research program conducted by the scientific contribution of Amirkabir University of Technology (Tehran Polytechnic) and the Technical University of Cluj-Napoca Romania aiming at developing sustainable Self-Consolidating Concrete (SCC) mixtures for using in concrete New Jersey barriers. The research program included an assessment on the fresh and hardened properties of: C25/30, C35/45, C40/50, and C50/60 strength classes of concrete mixtures to be used in the prefabrication of concrete New Jersey barriers. Cement contents of the mixtures varied between 510 to 410 kg of cement/m3 and silica fume was also applied in the mixtures as another component with cementitious characteristics. Three gradations based on the aggregates extracted from the local resource were considered. The additives were air-entraining agents and superplasticizer; the amount of the latter was tuned to meet a minimum of 550 mm to 660 mm slump flow in each mixture. High early strength (which is a necessity for most prefabricated concrete products) of the mixtures were compared. In order to ensure a sustainable design for the SCC mixtures, deterioration of the hardened concrete exposed to deicing chemicals in freeze-thaw cycles which is of high importance according to the national and European codes was measured. As well, Rapid Chloride Permeability Tests (RCPT) were also conducted and the results are presented.

Keywords: Self-Consolidating Concrete (SCC), New Jersey barriers, air-entraining agents, Freeze-thaw cycles, Rapid Chloride Permeability Tests