Hydration Properties and Physical Characteristics of Belite Cements

Abstract

In 2019 global cement production has been estimated at 4.1 billion tonnes and CO2 emissions from cement plants were nearly 3.0 billion tonnes. Belite-rich Portland cements (BPCs) have been suggested as innovative environmentally-friendly materials, inasmuch as they can allow a reduction of CO2-emissions up to 35% with respect to ordinary Portland cements (OPCs); in fact, the manufacturing process of BPCs, compared to that of OPCs, is characterized by reduced limestone requirement, lower synthesis temperatures and decreased specific fuel consumption. The peculiar composition of BPCs can be also exploited for achieving valuable technical properties (e.g. better durability against sulfate and carbonation attacks as well as low heat of hydration). This paper examined the hydration behaviour and the physical characteristics of a pilot-scale industrial belite cement hydrated with different water/cement ratios (w/c=0.35 and 0.50) for curing times comprised in the interval 2-90 days; an OPC (class 52.5 R), hydrated with a w/c=0.5, has been employed as a reference term. The experimental findings showed that BPCs systems had better performances, especially at the longest curing periods.