This study addresses an experimental approach to stabilizing clay soils with lime.In the preliminary stage and in order to require characteristic properties,untreated clay and sand samples are collected on site and su...This study addresses an experimental approach to stabilizing clay soils with lime.In the preliminary stage and in order to require characteristic properties,untreated clay and sand samples are collected on site and subjected to laboratory identification tests.Then,the so-called“trial and error”process based on production test series is used to mix with water by varying the proportions of the constituents.Using a manual press with a capacity of 5 to 10 tonnes,equipped with a 10×15×28 cm^(3) mould,the free-standing and heavy blocks are produced from the firm mixtures retained.After cures of 7,14 and 28 days,the results of the tests show that the resistance to compression(RC)of the blocks in the dry state increases depending on the lime dosage and the duration of cure.At 6%lime and around 25%sand,the value of the RC of 4,966 MPa after 28 days is higher than the recommended values for load-bearing walls by the Construction Materials Center(CMC)of N’Djamena(2.4 MPa)and CRATerre(4.0 MPa).On the other hand,a 24-h stay of the dry blocks in the water causes the RC to fall from 69%to 72%depending on the lime dosage.However,the absorption coefficient of 2.23 g/cm^(2)·s^(1/2) of blocks with 6%lime is much less than 20 g/cm^(2)·s^(1/2),limit value below which the NFP554 standard qualifies the low capillarity blocks.In short,this stabilization approach makes it possible to obtain blocks resistant to aesthetic appearance,low capillarity and cost to build walls.展开更多
文摘This study addresses an experimental approach to stabilizing clay soils with lime.In the preliminary stage and in order to require characteristic properties,untreated clay and sand samples are collected on site and subjected to laboratory identification tests.Then,the so-called“trial and error”process based on production test series is used to mix with water by varying the proportions of the constituents.Using a manual press with a capacity of 5 to 10 tonnes,equipped with a 10×15×28 cm^(3) mould,the free-standing and heavy blocks are produced from the firm mixtures retained.After cures of 7,14 and 28 days,the results of the tests show that the resistance to compression(RC)of the blocks in the dry state increases depending on the lime dosage and the duration of cure.At 6%lime and around 25%sand,the value of the RC of 4,966 MPa after 28 days is higher than the recommended values for load-bearing walls by the Construction Materials Center(CMC)of N’Djamena(2.4 MPa)and CRATerre(4.0 MPa).On the other hand,a 24-h stay of the dry blocks in the water causes the RC to fall from 69%to 72%depending on the lime dosage.However,the absorption coefficient of 2.23 g/cm^(2)·s^(1/2) of blocks with 6%lime is much less than 20 g/cm^(2)·s^(1/2),limit value below which the NFP554 standard qualifies the low capillarity blocks.In short,this stabilization approach makes it possible to obtain blocks resistant to aesthetic appearance,low capillarity and cost to build walls.
