Engineering geology of cinder gravel in Ethiopia: prospecting, testing and application to low-volume roads

Abstract

Expansion of the rural road network in Ethiopia requires the availability of low-cost materials for road construction, including capping layer and subgrade improvement, sub-base, base course, gravel wearing course and bituminised surface treatment. A reluctance to use cinder gravels for these purposes in the past has stemmed from the view that their properties, in terms of grading and CBR strength, are marginal and highly variable when compared to international specifications for road works. The geographical variability in Ethiopian cinder gravel geochemistry and engineering properties is described and comparisons are made with engineering geological field descriptions and cinder cone morphology, leading to the conclusion that maars and steep-sided, well-defined cones tend to yield the better-quality materials. The performance of trial sections of road constructed using cinder gravel is assessed and combined with the results of laboratory testing to develop a guideline for the wider use of the material in roadworks, either directly or through processes of blending, alternative compaction methods and cement stabilisation to yield a product that can be considered Bfit for purpose^for a range of uses in low-volume road construction.

Consolidation Attributes and Deformation Response of Soft Clay Reinforced with Vertical Scoria Drains under Road Embankment

“…It is also similarly used as a cement additive in the construction of reinforced concrete structures to improve the engineering properties of concrete [32][33][34]. Hossain and Hearn et al [32,35] reported that the blending of scoria as an additive material in concrete works proved efective in improving the strength, durability, and heat insulation properties of the concrete. Saltan and Ozen [36] in the experimental study on the usability of scoria as a subbase material reported the appropriateness of scoria as a partial replacement.…”

Potential Use of Scoria as a Cementitious Material for Green Concrete Production

“…Terefore, requirements for economical and more environmental-friendly cementing materials have extended interest in other cementing materials that can be used as alternatives to Portland cement which is available around constructing infrastructure. Historically, numerous kinds of volcanic scoria have been efectively utilized in dams and aqueducts, where the strength demand is not high but the durability and thermal cracking control are of major concern [2,3].…”

A study on the applicability of scoria gravel an alternative base course material through blending with marble waste aggregate

“…Scoria is a volcanic product that is abundantly available in various parts of the world such as; Turkey, Algeria, Papua New Guinea, Syria, Saudi Arabia, Cameroon, Indonesia, Rwanda, Tanzania, Yemen, Ethiopia, and many other subtropical countries [ 10 ]. In Ethiopia, Scoria gravel is extensively found especially in the Great Rift Valley, which crosses the northeastern part of the country including Akaki, Bishoftu, Mojo, Lake Ziway, Lake Chamo, Woliso, Butajira, Bekoji, Loggia, and Adama [ 11 , 12 ]. Because of its lightweight, rough circular surface, and high porosity, scoria gravel is vulnerable to compaction.…”