تطوير خرسانة خضراء خفيفة الوزن باستخدام حصويات بوزولانية: تقييم الخصائص الفيزيائية والميكانيكية.

Abstract

Concrete is considered one of the most widely used building materials in the world, but it is known to have a significant environmental impact due to the high carbon emissions associated with cement production. This research highlights the possibility of producing lightweight and sustainable concrete by replacing cement with natural pozzolana in the binder mixture in proportions ranging from (10-50%) with a complete change in the aggregate structure according to three groups, including pozzolanic gravel and sand or basaltic gravel. It discusses their effects on the physical and mechanical properties of the resulting concrete.

The study has shown that the pozzolanic aggregate structure with ground pozzolana used in the binder mixture, which reduces the carbon footprint of the concrete by using less cement, improves the physical properties of the concrete represented by workability and absorption capacity due to the low water demand of ground pozzolana. The results of absorption measurements showed that increasing the replacement percentage of cement with natural pozzolana in the binder mixture leads to a decrease in absorption in all mixtures at a replacement percentage of 50%, achieving percentages of (5.4, 11.3, 15.1%) for the first group (natural gravel and silica sand), the second group (pozzolanic gravel and basalt sand), and the third group (gravel and pozzolanic sand) respectively.

As for the mechanical properties represented by the compressive strength at 28 days, we notice a decrease when replacing cement with pozzolana due to the lower efficiency factor of ground pozzolana. However, the value of this resistance did not fall below the minimum limits of the standard specification for cement blocks, allowing the production of lightweight and environmentally friendly cement blocks using natural materials.