Application of wood waste ash in concrete making: revisited

Portland cement production is a carbon dioxide trigger responsible for almost 5% of the worlds CO2 emissions. Pozzolanic inclusions could contribute to sustainability particularly if they are derived from waste. Managing solid waste is increasingly becoming a global challenge as a result of increasing volume of accumulated waste from industrial and agricultural by-products. Environmental concerns as well as economic implications related with disposal of these wastes have prompted many researches in order to provide viable solutions. Recycling of these waste materials into the construction industry seems to be a more promising and viable alternative most especially in the manufacturing of greener and sustainable concrete material. Wood ash (WA) is a by-product derived from incineration of wood as well as its products such as sawdust, wood bark and chips. This paper presents an overview on investigations performed on the applicability of this material in mortar and concrete making. Specifics on physical, chemical, mineralogical and elemental characteristics of the waste material are discussed. It highpoints the impact of wood ash on workability, compressive and flexure strengths, water absorption, drying shrinkage, carbonation, alkali–silica reaction (ASR) and chloride permeability of concrete

Architecture, Space and Information in Constructions Built by Humans and Social Insects: a Conceptual Review

The similarities between the structures built by social insects and by humans have led to a convergence of interests between biologists and architects. This new, de facto interdisciplinary community of scholars needs a common terminology and theoretical framework in which to ground its work. In this conceptually oriented review paper, we review the terms “information”, “space” and “architecture” to provide definitions that span biology and architecture. A framework is proposed on which interdisciplinary exchange may be better served, with the view that this will aid better cross fertilisation between disciplines, working in the areas of collective behaviour and analysis of the structures and edifices constructed by non-humans; and to facilitate how this area of study may better contribute to the field of architecture. We then use these definitions to discuss the informational content of constructions built by organisms and the influence these have on behaviour, and vice versa. We review how spatial constraints inform and influence interaction between an organism and its environment, and examine the reciprocity of space and information on construction and the behaviour of humans and social insects

MOUND SOIL AS A PAVEMENT MATERIAL

The result of a study on some characteristics of laterite- cement mix containing termite mound soil (50% by weight of laterite) as replacement of laterite are presented in this paper. The study showed that laterite-mound soil mix stabilized with 6% cement could serve as a base course for roads for agricultural trafficking in rural areas where mound soils are abundant. At 6% cement stabilization the unconfined compressive strength (UCS) of 1.57 N/mm2 and a California bearing ratio (CBR) of 330% were obtained. The durability of the mix at this cement content was also found to be satisfactory with 87.7% resistance to loss in strength, and 1% weight loss and 1.15% volume change after 12 wet- dry cycle test. Key Words: Mound soil, Pavement, Road-base, Material [Global Jnl Engineering Res. Vol.1(2) 2002: 137-144

CEMENT KILN DUST AS A MATERIAL FOR BUILDING BLOCKS

This paper presents the results of a study on the properties of hollow sandcrete blocks with cement kiln dust (CKD) as an additive and as a replacement for ordinary portland cement (OPC). When CKD was used as a replacement for cement, the compressive strength and density of blocks generally decreased with higher replacement levels of OPC by CKD, while the percentage water absorption of blocks increased with higher replacement levels. On the other hand, when CKD was used as additive, within the investigated levels, an improvement in the compressive strength of up to 54% was observed. The density of blocks also increased with higher CKD content as additive, while the percentage water absorption of blocks showed a reverse trend. Key Words: Kiln Dust, Material, Building, Blocks, Construction [Global Jnl Engineering Res. Vol.1(1) 2002: 73-78