Four raw deposits clayey materials in Burkina Faso have been characterized using X-ray diffraction, infrared spectroscopy and ICP-AES to evaluate their suitability to be used as pozzolan in cement. The samples have be...Four raw deposits clayey materials in Burkina Faso have been characterized using X-ray diffraction, infrared spectroscopy and ICP-AES to evaluate their suitability to be used as pozzolan in cement. The samples have been activated by thermal treatment at 730°C during 5 hours. The obtained metakaolin was investigated by means of complementary techniques for their use as pozzolan in building materials. Fineness, surface area and amorphousness of metakaolins were the dominant factors which influenced their pozzolan reactivity. The compressive strengths of blended specimens were slightly increased with metakaolins named MK1 and MK2 than the reference for the substitution of 20 - 25 wt%. This was due to the metakaolins’ pozzolan reactivity and their filler effects which promoted CSH formation and reduced pores in the specimens. MK1 and MK2 were suitable for replacement of Portland cement in the field of building materials.展开更多
The purpose of this work is to study the influence of Rice Husk Ash (RHA) on the mechanical strength of mortars. For this purpose, ash was produced by calcining rice husk at 680°C for 5 hours to produce reacti...The purpose of this work is to study the influence of Rice Husk Ash (RHA) on the mechanical strength of mortars. For this purpose, ash was produced by calcining rice husk at 680°C for 5 hours to produce reactive pozzolan. The chemical and mineralogical composition studied by Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) and X-Ray Diffraction (XRD) showed that this ash is rich in amorphous silica. The ash presents a good pozzolanic activity with a lime fixation rate of 100% after only 7 days of treatment. The addition of RHA to cement contributes to the formation of calcium silicate hydrate (CSH) and calcium aluminate hydrate of C3ASH6 type. The presence of RHA in the mortars improves their mechanical strength. This improvement is due to the filler effect of RHA and to formation of the CSH resulting from the pozzolanic reactivity between the amorphous silica of the RHA and the portlandite released by hydration of the cement.展开更多
This paper deals with the elaboration of porous ceramic pots with raw clay materials and rice husks for water filtration. The basic raw clays have been mixed with rice husks at different ratio 10% and 15% weight (wt) ...This paper deals with the elaboration of porous ceramic pots with raw clay materials and rice husks for water filtration. The basic raw clays have been mixed with rice husks at different ratio 10% and 15% weight (wt) and sintering at 1200°C, 1300°C and 1400°C for 30 minutes. The elaborated pots have been tested for their densification properties and filtration flow. The mineralogy and microstructure of pot have been also studied to explain the different results. The pot with 10% wt rice husks and sintering at 1300°C during 30 minutes presents a sufficient porosity and mechanical strength to be used for water filtration.展开更多
文摘Four raw deposits clayey materials in Burkina Faso have been characterized using X-ray diffraction, infrared spectroscopy and ICP-AES to evaluate their suitability to be used as pozzolan in cement. The samples have been activated by thermal treatment at 730°C during 5 hours. The obtained metakaolin was investigated by means of complementary techniques for their use as pozzolan in building materials. Fineness, surface area and amorphousness of metakaolins were the dominant factors which influenced their pozzolan reactivity. The compressive strengths of blended specimens were slightly increased with metakaolins named MK1 and MK2 than the reference for the substitution of 20 - 25 wt%. This was due to the metakaolins’ pozzolan reactivity and their filler effects which promoted CSH formation and reduced pores in the specimens. MK1 and MK2 were suitable for replacement of Portland cement in the field of building materials.
文摘The purpose of this work is to study the influence of Rice Husk Ash (RHA) on the mechanical strength of mortars. For this purpose, ash was produced by calcining rice husk at 680°C for 5 hours to produce reactive pozzolan. The chemical and mineralogical composition studied by Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) and X-Ray Diffraction (XRD) showed that this ash is rich in amorphous silica. The ash presents a good pozzolanic activity with a lime fixation rate of 100% after only 7 days of treatment. The addition of RHA to cement contributes to the formation of calcium silicate hydrate (CSH) and calcium aluminate hydrate of C3ASH6 type. The presence of RHA in the mortars improves their mechanical strength. This improvement is due to the filler effect of RHA and to formation of the CSH resulting from the pozzolanic reactivity between the amorphous silica of the RHA and the portlandite released by hydration of the cement.
文摘This paper deals with the elaboration of porous ceramic pots with raw clay materials and rice husks for water filtration. The basic raw clays have been mixed with rice husks at different ratio 10% and 15% weight (wt) and sintering at 1200°C, 1300°C and 1400°C for 30 minutes. The elaborated pots have been tested for their densification properties and filtration flow. The mineralogy and microstructure of pot have been also studied to explain the different results. The pot with 10% wt rice husks and sintering at 1300°C during 30 minutes presents a sufficient porosity and mechanical strength to be used for water filtration.
