The study of the performances of the Archean of Man gneiss aggregates with the addition of filler to replace the basalt of Kasila group in the asphalt and concrete mix design of southern Sierra Leone is presented in t...The study of the performances of the Archean of Man gneiss aggregates with the addition of filler to replace the basalt of Kasila group in the asphalt and concrete mix design of southern Sierra Leone is presented in this document. The goal is to compare the results of the asphalt and concrete mix design with gneiss and basalt aggregate. The applied methods and design used are 1) Volumetric design and Marshall method for the asphalt, 2) French Dreux-Gorisse Method for the concrete. We added 2% of gneissic filler and 2% portland cement type 42.5 R to the asphalt hot mix with the gneiss aggregates to follow the criteria variation. The Marshall, the diametric compression and the Duriez tests require us to perform four different types of mix design. The four mix designs meet the requirements but F2 and F4 give the best mechanical properties. F2 (gneiss + 2% filler) and F4 (basalt) have many similarities from which we can conclude their interchangeability. F2 gives 5255 of optimal bitumen content. In regards to hydraulic concrete, the results of the compressive strength test (cement content 350 kg CMI 42.5 R/m3) with the gneiss and basalt aggregates are respectively 40 MPa and 45 MPa at 28 days curing: these values are greater than 35 MPa required by the technical specifications. The use of the Super Fluid ® Thermoplast 120 admixture, to increase the concrete compressive strength, is justified by the requirement of a minimum of 80% Rc28 at 24 hours. For both types of concrete, we have at 24 hours, 34 and 35 MPa which are higher than the minimum of 32 MPa (in 24 h). These results meet the requirements of the technical specifications.展开更多
The study of the performance of raw clay bricks has made it possible to develop laterite in Eco village construction projects.Identification tests(particle size analysis,Atterberg limits,Proctor,shrinkage limit,and sa...The study of the performance of raw clay bricks has made it possible to develop laterite in Eco village construction projects.Identification tests(particle size analysis,Atterberg limits,Proctor,shrinkage limit,and sand equivalent)made it possible to characterize the laterite,the sand,and the E1 mixture(70%laterite and 30%sand).By adding binders to E1,three other types of mixtures E2,E3,and E4 have been proposed.The improved E1 sample:(1)At 2.5%of cement gives E2;(2)At 10%of lime gives E3;(3)with 0.8%lignosulfonates.After making the bricks using the samples E1,E2,E3,and E4,we perform uniform compression test at 3,7,and 21 days.All samples have simple compressive strengths greater than 0.5 MPa(in accordance with standard NF EN 771-1)after 3 days.Their evolution from 0.5 to 2.5 MPa,between 3 and 7 days,shows a jump of 1.5.From 7 to 21 days the evolution curve of the Rc shows a slight ascension then a plateau pace(2.5,2.51,2.56 MPa).From these results,we concluded that they were used according to the area and the type of climate.The use of the sample E1 is proposed in arid zones or with low rainfall,the sample E2,and E3 in the rainy zones without risk of capillary rise and the sample E4 in the rainy zones with the risk of capillary rise.展开更多
文摘The study of the performances of the Archean of Man gneiss aggregates with the addition of filler to replace the basalt of Kasila group in the asphalt and concrete mix design of southern Sierra Leone is presented in this document. The goal is to compare the results of the asphalt and concrete mix design with gneiss and basalt aggregate. The applied methods and design used are 1) Volumetric design and Marshall method for the asphalt, 2) French Dreux-Gorisse Method for the concrete. We added 2% of gneissic filler and 2% portland cement type 42.5 R to the asphalt hot mix with the gneiss aggregates to follow the criteria variation. The Marshall, the diametric compression and the Duriez tests require us to perform four different types of mix design. The four mix designs meet the requirements but F2 and F4 give the best mechanical properties. F2 (gneiss + 2% filler) and F4 (basalt) have many similarities from which we can conclude their interchangeability. F2 gives 5255 of optimal bitumen content. In regards to hydraulic concrete, the results of the compressive strength test (cement content 350 kg CMI 42.5 R/m3) with the gneiss and basalt aggregates are respectively 40 MPa and 45 MPa at 28 days curing: these values are greater than 35 MPa required by the technical specifications. The use of the Super Fluid ® Thermoplast 120 admixture, to increase the concrete compressive strength, is justified by the requirement of a minimum of 80% Rc28 at 24 hours. For both types of concrete, we have at 24 hours, 34 and 35 MPa which are higher than the minimum of 32 MPa (in 24 h). These results meet the requirements of the technical specifications.
文摘The study of the performance of raw clay bricks has made it possible to develop laterite in Eco village construction projects.Identification tests(particle size analysis,Atterberg limits,Proctor,shrinkage limit,and sand equivalent)made it possible to characterize the laterite,the sand,and the E1 mixture(70%laterite and 30%sand).By adding binders to E1,three other types of mixtures E2,E3,and E4 have been proposed.The improved E1 sample:(1)At 2.5%of cement gives E2;(2)At 10%of lime gives E3;(3)with 0.8%lignosulfonates.After making the bricks using the samples E1,E2,E3,and E4,we perform uniform compression test at 3,7,and 21 days.All samples have simple compressive strengths greater than 0.5 MPa(in accordance with standard NF EN 771-1)after 3 days.Their evolution from 0.5 to 2.5 MPa,between 3 and 7 days,shows a jump of 1.5.From 7 to 21 days the evolution curve of the Rc shows a slight ascension then a plateau pace(2.5,2.51,2.56 MPa).From these results,we concluded that they were used according to the area and the type of climate.The use of the sample E1 is proposed in arid zones or with low rainfall,the sample E2,and E3 in the rainy zones without risk of capillary rise and the sample E4 in the rainy zones with the risk of capillary rise.
