Effect of chemical additives on consistency, infiltration rate and swelling characteristics of bentonite

Abstract

Problems associated with expansive soils in Egypt are predominantly related to the presence of montmorillonite clay minerals in the soil with fresh water. In this paper we are trying to solve the swelling problem of bentonite by using the chemical additives such as ammonium chloride, sodium chloride sodium carbonate and lime. This paper presents the results of an experimental investigation performed to quantify the effect of mixing bentonite which represent the swelling soil in homogenies phase with chemical additives such as ammonium chloride, sodium chloride sodium carbonate and lime on the consistency and swelling characteristics of bentonite. The results showed that the increase of the chemical concentration to about 20% of the total sample weight of the mixing water leads to major decrease in the liquid limit and swelling characteristics of the bentonite. The reduction in the swelling of the bentonite is also proportional to the rate of chemical water infiltration into the bentonite. As the increase of the ammonium chloride and lime leads to significant increase of the infiltration.

Improvement of Expansive Soil by Using Micro Silica Fume

“…It is composed of a disc fixed to a rod with a load of 136 gm slides alongside of the rod, falls from 150 mm height and comes to strike the disc to compact the mixture. Therefore, to prepare the expansive soil-additive mixture samples for testing, these samples were oven dried at 105ºc [1], then weighted according to the maximum dry unit weight of the soil and the chosen percentage of additive and physical mixing for 10 minutes to each portion was adopted. Finally, the weighted amount of the mixture is compacted using the tool described previously in two layers with the same compaction energy.…”

“…Swelling soils is the generic description of all soils containing montmorillonite mineral. Swelling soil deposits are mainly found near the arid areas of Egypt including the regions extending around the Nile valley in Upper Egypt [1]. Swelling soils, also known as expansive soils or reactive soils, composed predominantly of high percentage of fine-grained clay particles.…”

“…Gupta and Sharma, 2014 [3] investigated the effect of adding micro silica fume on the shear strength of expansive soil to be used as a sub grade material for construction of flexible pavements in rural roads with low traffic volume. An experimental investigation was performed to quantify the effect of mixing bentonite as a swelling soil with chemical additives such as sodium chloride, lime, sodium carbonate and ammonium chloride by Elmashad, 2017 [1]. Sakr et al, 2020 investigated the effect of using nanoclay [4] and micro metakaolin [5] on reducing the swelling potential of expansive soils.…”

Experimental Study on the Effect of Micro-metakaolin on the Strength and Swelling Characteristics of Expansive Soils

“…Gupta and Sharma (2014) investigated the effect of adding micro silica fume on the shear strength of expansive soil used as subgrade material for construction of exible pavements in rural roads with low tra c volume. Elmashad (2017) performed an experimental investigation was performed to quantify the effect of mixing bentonite as an expansive soil with chemical additives such as sodium chloride, lime, sodium carbonate and ammonium chloride. Also, the effect of polyvinyl alcohol and potassium carbonate on improving the expansive soil was discussed (Zhang et al, 2019) A review of the emerging trends in expansive soil stabilization such as chemical techniques and solid wastes was studied by Ikeagwuani and Nwonu (2019).…”

Study on prevention and treatment of capillary water rise for construction waste expansive soil subgrade

“…According to the research on the damage mechanism of expansive soil subgrade ( Hu et al., 2019 ; Elmashad and Eldin, 2017 ; Anifowose, 1996 ), it is found that the damage of expansive soil subgrade is mainly caused by rainfall, especially when the rain penetrates the subgrade bottom and contacts the extended soil cushion, a thick fluffy layer will be produced. As a highly hydrophilic soil, bentonite can quickly form an ultra-high capillary water elevation line ( Rafalski, 1994 ; Nurus et al., 2016 ; Lubelli et al., 2013 ).…”