Sustainability starts from the building material

Study of micronized sand as a cement replacement

Fig. 1. Particle size distribution of four micronized sands:
M6, M10, M300 and M600.

Fig. 2 M6, magnification 200x (left), and M600 at 2000x (right).

Fig. 2. M6, magnification 200x (left), and M600 at 2000x (right).

Fig. 3 Viscosity vs. replacement level (a) and relative strength loss vs. replacement (b).

Fig. 3 . Viscosity vs. replacement level (a) and relative strength loss vs. replacement (b).

Fig. 4 Maximum packing density (calculated) versus maximum aggregate size (a) and calculated particle packing of different M600-M6-CEM I mixtures (b).

Fig. 4. Maximum packing density (calculated) versus maximum aggregate size (a) and calculated particle packing of different M600-M6-CEM I mixtures (b).

Fig. 5 Comparison of calculated contact area (left axis) and compressive strength at 7 days (right axis) for increasing replacement by M600 (a) and increasing fineness of MS (b).

Fig. 5. Comparison of calculated contact area (left axis) and compressive strength at 7 days (right axis) for increasing replacement by M600 (a) and increasing fineness of MS (b).

Fig. 6 . ESEM images of the interface between hydrating cement and MS [11].

Fig. 6 ESEM images of the interface between hydrating cement and MS [11].

Due to the high level of CO₂ emissions and scarcity or raw materials involved in the production of cement, ways are being sought to reduce the amount of cement needed. In this paper, micronized sand is investigated as a cement replacement. The material properties are determined and the influence on the cement paste assessed through workability and strength measurements. It is found that workability decreases with increasing fineness and higher replacement levels.

The environmental impact of infrastructure projects is becoming an increasingly important issue in engineering design. There is a growing pressure from governments and owners/clients to realize infrastructure that meets the needs of today’s communities without compromising the needs of future generations. This means that, in the future, construction materials will be selected on the basis of the contribution they can make to meet sustainability requirements. Today, Portland cement is still the essential component of concrete. The CO₂emissions generated by cement production amount to more than...