Durability of Stabilized Earthen Constructions: A Review

Abstract

It has become general practice to stabilize earthen materials with chemical binders, since one of their main weaknesses is their lack of durability. The most commonly used stabilizer is cement, which reinforces earth by enhancing its strength and water resistance with chemical bonds, while at the same time significantly increases its embodied energy and reduces its sorption capacity. These side-effects greatly reduce the sustainability appeal of earthen materials, leading to a contradiction in this application of cement. Since the researcher community has been aware of this more and more results are published of experiments with alternative stabilizers. This review provides an overview of research about the durability of stabilized earthen walls, the methods used to assess it and parameters that have been shown to affect it. The review features a brief history of this field, but focuses more on recently published data about the water erosion performance of stabilized earthen construction materials. Conclusions about the existing test methods are drawn, with directions for further development suggested.

Hydric and Durability Performances of Compressed Earth Blocks Stabilized with Industrial and Agro By-Product Binders: Calcium Carbide Residue and Rice Husk Ash

“…Earthen materials, particularly compressed earth blocks (CEBs), are currently regaining the global popularity in modern building constructions for abiding by environmental sustainability and circular economy. However, the society still has some wrong perceptions about the raw earth for construction, considering it as the material for the poor and/or less durable (Beckett et al 2020;Dahmen 2015;Hughes et al 2017;Medvey and Dobszay 2020;Morel and Charef 2019). The current popularity of earth is highlighted by the exponential increase of the scientific studies of earth-based construction materials and techniques, and durability testing methods (Beckett et al 2020;Medvey and Dobszay 2020).…”

“…However, the society still has some wrong perceptions about the raw earth for construction, considering it as the material for the poor and/or less durable (Beckett et al 2020;Dahmen 2015;Hughes et al 2017;Medvey and Dobszay 2020;Morel and Charef 2019). The current popularity of earth is highlighted by the exponential increase of the scientific studies of earth-based construction materials and techniques, and durability testing methods (Beckett et al 2020;Medvey and Dobszay 2020). Among various techniques, the stabilization using chemical binders such as cement, lime, pozzolanic or alkaline-activated binders not only improves the mechanical properties, but also the hydric and durability indicators of earthen material (Abhilash et al 2020;Beckett et al 2020;Bogas et al 2018;Gomes et al 2016;Mango-Itulamya et al 2020;Sore et al 2018).…”

“…The tests of the durability of earthen materials, particularly CEBs, are most commonly carried out in the laboratory vis-a-vis water ingress, either by capillary or total absorption, water erosion (spray or drip test), wetting-drying cycles (wire brush test), freeze-thaw cycles, as well as other tests in outdoor real conditions (Beckett et al 2020;Medvey and Dobszay 2020). Additionally, the resistance to surface abrasion and mechanical resistance, in dry or wet conditions, can clearly indicate the durability of earthen material (AFNor 2001;CDI&CRATerre 1998).…”

“…While the stabilization using chemical industrial binders like cement and/or lime generally improves the durability of stabilized CEBs, these binders are scrutinized to increase the embodied energy and CO2 emission and thus tempering with the sustainability and other advantages of raw earthen materials (Arrigoni et al 2017a;Medvey and Dobszay 2020).…”

“…Therefore, further investigations have been carried out on alternative stabilization approaches and binders that can allow to improve different durability indicators of earth, with relatively limited environmental impact (Al-Fakih et al 2019;Medvey and Dobszay 2020). These attempts consist of incorporating aggregates or by-product binders from different origins in the earthen materials (Abhilash et al 2020;Arrigoni et al 2017a;Azeko et al 2018;Bogas et al 2018;Latifi et al 2018 ;Mango-Itulamya et al 2020;Masuka et al 2018;Seco et al 2017).…”