Local Materials Promotion Authority MIPROMALO
Local Materials Promotion Authority MIPROMALO
Tsozue D.,University of Maroua |
Nzeugang A.N.,Local Materials Promotion Authority MIPROMALO |
Mache J.R.,Local Materials Promotion Authority MIPROMALO |
Loweh S.,Local Materials Promotion Authority MIPROMALO |
Fagel N.,Laboratory of Clays
Journal of Building Engineering | Year: 2017
This article summarized some characteristics of clayey materials from semi-arid climate in Far North Cameroon and evaluated their use in ceramic bricks production. Three samples (Ma1, Ma2 and Ma3) were characterized using XRD, FTIR, XRF and firing at 900, 1000 and 1100 °C. SiO2 (~64–75%), Al2O3 (~12–15%), Fe2O3 (~2–5%) and (~7%) of fluxing agents (K2O, CaO, Na2O) were the predominant oxides with a reduce contents in Ma3. Quartz (~40%), K-feldspar (~25%) and plagioclase (~14%) were non-clay minerals while clays minerals were mainly kaolinite (~4–10%), illite (~4–7%) and smectite (~2–7%). Ma1 and Ma2 are similar in terms of mineralogy, particle size distribution and plasticity. Sample M3 is most sandy (65%) and less plastic (2.3%). After firing Ma1 and Ma2 provided good technological properties compared to Ma3. At 1000 °C for example, they displayed a metallic sound, bulk density of 1.8 g/cm3, a linear shrinkage <5%, water absorption of 13% and flexural strength >5 MPa. Mixing Ma3 with other samples (up to 50%) substantially improved the quality of the firing specimens for making construction bricks. © 2017 Elsevier Ltd
Kamseu E.,University of Modena and Reggio Emilia |
Beleuk a Moungam L.M.,Local Materials Promotion Authority MIPROMALO |
Cannio M.,University of Modena and Reggio Emilia |
Billong N.,Local Materials Promotion Authority MIPROMALO |
And 3 more authors.
Journal of Cleaner Production | Year: 2017
Rice husk ash (RHA), a by-product from the rice industry, was used as principal source of amorphous silica for the production of sodium silicate solution (MR ∼ 3) used for the replacement of standard commercial sodium silicate in the mix-design of metakaolin based geopolymer composites. Three initial concentrations of NaOH were considered (8, 10 and 12 M) with the aim to investigate on the optimum dissolution and formation of silica oligomers capable to act as binder during the geopolymerization. Results (FT-IR and XRD) showed that RHA-NaOH sodium silicate solutions have characteristics similar to that of standard commercial sodium silicate and the residual carbonates present in the viscous pastes can be monitored during the preparation of geopolymers using the mix-design. Combined 25 vol% standard sodium silicate solution with ∼75 vol% of RHA-NaOH based sodium silicate solution conducted to good polycondensation, densification, high flexural strength (∼8 MPa) and low porosity similar to that of the standard matrix of metakaolin based composites. The new approach is found promising for the significant reduction of the Global Warming Potential of Geopolymers. © 2016
Fongang R.T.T.,University of Yaounde I |
Pemndje J.,Local Materials Promotion Authority MIPROMALO |
Lemougna P.N.,Local Materials Promotion Authority MIPROMALO |
Melo U.C.,Local Materials Promotion Authority MIPROMALO |
And 5 more authors.
Energy and Buildings | Year: 2015
Inorganic polymer cement paste was used as cleaner binder for the design of lightweight matrices as insulating envelopes and panels in building and construction industries. Sponge-like structure with a homogeneously distributed pore network, low density and low thermal conductivity permitted to classify the geopolymer-wood fiber composites promising clean insulating materials. Matrices with the density ∼0.79 g/cm3, bi-axial four-point flexural strength of ∼4 MPa presented thermal conductivity between 0.2 and 0.3 W/(m K). The possibility of substituting the sodium silicate with rice ash-NaOH system and the efficiency of the matrices to constitute an effective tortuous road for the thermal gradient improved the sustainability and quality of this new class of products. The pores network and the microstructure approximated by a spatial periodic geometry suggested a "macro transport" mechanism to explain the movement of heat across the matrix of light geopolymer composite. © 2015 Elsevier B.V. All rights reserved.
Nzeugang Nzeukou A.,Laboratory of Clays |
Nzeugang Nzeukou A.,Laboratory of Alterology and Engineering Geology |
Fagel N.,Laboratory of Clays |
Njoya A.,University of Dschang |
And 4 more authors.
Applied Clay Science | Year: 2013
Alluvial clays from four localities along the Sanaga River (Center Cameroon) were studied by physico-chemical, mineralogical and technological characterization in order to assess their suitability as ceramic raw materials. The chemical compositions indicated that SiO2 (65-70%) and Al2O3 (12-15%) are major elements while Fe2O3 is less (4-7%). Kaolinite, quartz and feldspar are the main minerals. Particle size distribution and chemical composition are indicative of "plastic red clays" belonging to heavy sandy clays group. Their medium to high plasticity is suitable for fired earth and fine ceramics products. Pressed samples were fired at temperatures ranging between 900 and 1100°C for coarse ceramic products. Linear shrinkage, flexural strength and water absorption indicated that the clays from one site (Mbandjock) are good for brick making. Clays from the three other localities present poor technological properties (higher shrinkage and cracks), they need degreasers before use as ceramic raw materials. Although water absorption and flexural strength parameters are good for all the studied samples, firing shrinkage needs to be improved. © 2013 Elsevier B.V.