Cardboard as a construction material: a case study

A small cardboard building with a 25-year intended lifetime was developed as a live innovation project to explore and resolve the practical problems surrounding the design, fabrication and construction, costs, and use of an alternative building material. The primary aim to reduce environmental impacts was based on developing the potential of a recycled material as the main structural and cladding component that could be further recycled at the end of its working life. This case study of a small school building presents both the research and development undertaken by the project team and the practical implications of realizing this as a building for a client.     

Simple durability test for cement stabilized blocks

Compressed and cement-stabilized blocks are now recognized as important walling units for building low-cost dwellings in developing countries. Although the durability of their surfaces under in-service exposure conditions in the humid tropics has become a major matter of concern, it has received little formal research. Premature deterioration - as typified by surface erosion, mass loss, pitting, cracking and crazing - is common. A weather-resistant surface is required if a block is to remain durable for its service lifetime. However, current accelerated ageing tests to predict the overall performance of blocks under conditions causing surface deterioration (wetting, abrasion and drying) are inadequate. A new method is required that can be applied to blocks immediately after curing to evaluate the likely durability of their surfaces. The present paper explores the suitability of using the slake-durability test, originally developed for argillaceous rocks, to evaluate the durability of low-cost walling materials. During the test, surface erosion leading to mass loss of between 1 and 50% is recorded within only 10 minutes, representing an acceleration of in-service ageing by a factor of around 1 million. The test method proved reliable, controllable and repeatable. More importantly, the ranking of materials via their performance in this test correlated well with a ranking of their durability in service based on long professional field experience in Uganda. It is concluded that the slake-durability test not only is robust, but also provides a quick predictive surface and quality test for cement-stabilized blocks and other like materials.