Appropriate Use of Lime in the Study of the Physicochemical Behaviour of Stabilised Lateritic Soil under Continuous Water Ingress

Sustainability

Abiola Johnson¹  Chukwueloka Okeke¹  Samuel Abbey²  Eyo Eyo²  Mgboawaji Ujile²  Tamunoene Abam³  Samson Ngambi⁴  Jonathan Oti⁵ 

[1] Department of Civil Engineering, College of Engineering, Covenant University, Ota P.M.B. 1023, Nigeria;Faculty of Environment and Technology, Department of Geography and Environmental Management, Civil Engineering Cluster, University of the West of England, Bristol BS16 1QY, UK;Institute of Geosciences and Space Technology, Rivers State University, Nkpolu-Oroworukwo, Port Harcourt P.M.B. 5080, Nigeria;School of Energy, Construction and Environment, Faculty of Engineering, Environment and Computing, Coventry University, Coventry CV1 5FB, UK;School of Engineering, Faculty of Computing, Engineering and Science, University of South Wales, Pontypridd CF37 1DL, UK;

关键词: lateritic soil;    lime stabilization;    subgrade;    leaching;    CBR value;    durability;   

DOI  :  10.3390/su13010257

来源: DOAJ

【 摘 要 】

Lime stabilisation is one of the traditional methods of improving the engineering properties of lateritic soils for use as subgrade and foundation materials for the construction of road pavements and highway embankments. Understanding the mechanical performance of lime-stabilised lateritic subgrades in terms of their durability under continuous water ingress will improve environmental sustainability by conserving scarce natural resources and reducing the environmental impacts of repair and replacement of pavements. However, there are several conflicting reports on the durability of lime-stabilised soils subjected to continuous water ingress and harsh environmental conditions. Therefore, this paper evaluates the influence of leaching on the physicochemical behaviour and durability of lime-stabilised lateritic soil under continuous water ingress, simulating the typical experience in a tropical environment. Variations in the strength and durability of the lateritic soil at various lime contents (0, 2.5, 5, 7.5, 10, 15, and 20 wt.%) and soaking periods (3, 7, 14 and 28 days) were evaluated by performing the California bearing ratio tests before and after subjecting the lime-lateritic soil (LLS) samples to continuous leaching using two modified leaching cells. Furthermore, physicochemical analysis was performed to assess the variation of cation concentrations and changes in the physical properties of the pore fluid as the leaching time progressed from 3 to 28 days. The results show that the minimum strength reduction index of the soil corresponds to its lime stabilisation optimum (LSO). Electrical conductivity decreased monotonically and almost uniformly with an increase in leaching time, irrespective of lime content. So, too, was calcium concentration and to a lesser degree for pH and potassium concentration. Adverse changes in the physicochemical behaviour of the LLS samples occurred at lime contents below and slightly above the optimum lime content of the soil. Whereas permanent pozzolanic reactions occurred at lime contents above the LSO and thus resulted in a 45-fold increase in strength and durability. The results are significant for reducing the detrimental effect of the leaching-induced deterioration of flexible pavements founded on tropical floodplains.

【 授权许可】

Unknown