Affordable and Sustainable Housing in Rwanda

Clement Egenti,Jamal Khatib

doi:10.3390/su13084188

Abstract

Baked clay bricks (Impunyu) is the dominant wall construction material in Rwanda. Clay deposits in the country’s lowlands are utilized for baked clay bricks. Despite the ongoing campaign, the use of wood by some local brick producers is unfriendly to the environment. Recent research has called for alternative methods in order to reduce the cost and impact on the environment. Earlier efforts with compressed earth blocks were saddled with weight and a substantial use of cement for good surface texture and adequate resistance against surface erosion. This research explored the potentials of using an appropriate dose of clay (from Muhanzi), volcanic light aggregate (Amakoro, (from Musanze)), and cement to produce unbaked shelled compressed earth blocks (SCEB). SCEB is a compressed earth block with an outer shell and inner core of different cement content or materials, compressed into a unit block. The result is a masonry unit with a higher surface resistance, durability, and desirable architectural effect produced with a 60% reduction in cement content. A weight reduction of 12% was achieved with an optimum content of 33% of the volcanic lightweight aggregate. A cost reduction of 25% was recorded over conventional compressed earth brick walls and a 54% over sand-cement block walls. Possible future trends were also identified with appreciable prospects in earthen architecture.

Highlights

In Rwanda, about 75% of buildings are constructed with baked clay bricks [1]
This research explored the potentials of using an appropriate dose of clay, volcanic light aggregate (Amakoro,), and cement to produce unbaked shelled compressed earth blocks (SCEB)
The result is a masonry unit with a higher surface resistance, durability, and desirable architectural effect produced with a 60% reduction in cement content

Summary

Introduction

In Rwanda, about 75% of buildings are constructed with baked clay bricks [1]. The industrial subsector Masterplan for Construction Materials for Rwanda identified an abundance of available local construction materials, such as clay, wood, sand, and stone [2].The hilly terrain of Rwanda creates a natural movement of surface water from the hills to the valley. In Rwanda, about 75% of buildings are constructed with baked clay bricks [1]. The industrial subsector Masterplan for Construction Materials for Rwanda identified an abundance of available local construction materials, such as clay, wood, sand, and stone [2]. The hilly terrain of Rwanda creates a natural movement of surface water from the hills to the valley. The efforts to utilize the existing local materials may well explain the popularity of baked clay bricks in the construction industry. While the formal brick industries are conscious of environmental issues posed by choice of firing materials by the use of rice or coffee husks (waste biomaterials), the informal local brick producers most often use wood with environmental effect on the forests. Since poor people directly depend on natural resources and natural services for their survival, a clear link between poverty reduction and environmental degradation is established [4]

Objectives

Methods

Results

Conclusion