Effects of portland cement replacement with limestone on the properties of hardened concrete

Limestone portland cement has a lower environmental impact during the production phase in comparison with portland cement. However, the environmental advantages initially gained should be correlated to the long-term performance of concrete structures. Hence, the knowledge of the long-term properties, and in particular durability performance, is essential to assess the actual environmental impact of limestone replacement. In the literature, there is disagreement on durability behaviour and the contribution of limestone to the resistance to chloride and carbonation penetration is controversial. In this paper, the effect of the percentage of replacement of portland cement with ground limestone, water/binder ratio and cement content on compressive strength, electrical resistivity, sorptivity and resistance to carbonation and chloride penetration was evaluated. Results showed that both mechanical properties and resistance to penetration of aggressive agents decreased by replacing 15% of portland cement with limestone; a further decrease occurred with 30% limestone.