Everton Silva

Effect of milling process for rice husk ash on mechanical strength of blended Portland cement mortars

Nowadays, the reuse of waste products in the construction process is a priority research area. Several industrial and agricultural waste products have been investigated, such as fly ash, sugar cane bagasse ash and rice husk ash. This paper analyzes a very important aspect under intense discussion in the scientific community: the Rice Husk Ash (RHA) grinding process. This paper investigates a low carbon RHA with high pozzolanic reactivity produced under uncontrolled burning conditions. The compressive strength of mortar specimens prepared using both ground and natural RHA were tested for 3-56 days and the capillarity absorption was measured for mortars cured during 28 days. Very promising and interesting results were obtained using natural rice husk ash in the production of blended mortars.

Variables Involved in the Planting of Rice in the Rice Husk

Rice production in Brazil in 2010 was approximately 12,2 million tons, and to reach that amount several planting techniques were used with different strains of rice in different rice-growing areas. Since Rice Husk Ash (RHA) is the pozzolan of vegetable origin most studied by researchers working in the area of pozzolanic materials, the present paper evaluates the influence that the form of planting, the climate, the soil, the strain of rice and the origin/amount of nitrogen-based fertilizers used in rice cultivation has on the chemical composition and crystallographic properties of RHA. The results obtained in this paper, confirm the importance of carrying out routine chemical analysis and X-Ray diffraction to maintain the quality control of the CCAs produced, because in situations of large-scale production, husks of different origins may be used.