Thermal conductivity and compressive strength of concrete incorporation with mineral admixtures

Civil Engineering Department, Engineering Faculty, Atatürk University, 25240 Erzurum, Turkey
Building and Environment 01/2007; DOI: 10.1016/j.buildenv.2006.06.010

ABSTRACT In this study, the effect of silica fume (SF), class C fly ash (FA), blast furnace slag (BFS), SF+FA, SF+BFS, and FA+BFS on the thermal conductivity (TC) and compressive strength of concrete were investigated. Density decreased with the replacement of mineral admixtures at all levels of replacements. The maximum TC of 1.233 W/mK was observed with the samples containing plain cement. It decreased with the increase of SF, FA, BFS, SF+FA, SF+BFS, and FA+BFS. The maximum reduction was, 23%, observed at 30% FA. Compressive strength decreased with 3-day curing period for all mineral admixtures and at all levels of replacements. However, with increasing of curing period reductions decreased and for 7.5% SF, 15% SF, 15% BFS, 7.5% SF+7.5% FA, 7.5% SF+7.5% BFS replacement levels compressive strength increased at 28 days, 7- and 28-days, 120 days, 28- and 120 days, 28 days curing periods, respectively. Maximum compressive strength was observed at 15% BFS replacement at curing period of 120 days.

1 Bookmark
  • [Show abstract] [Hide abstract]
    ABSTRACT: The effects of high temperature on the mechanical properties of cement based mortars containing pumice and fly ash were investigated in this research. Four different mortar mixtures with varying amounts of fly ash were exposed to high temperatures of 300, 600, and 900 °C for 3 h. The residual strength of these specimens was determined after cooling by water soaking or by air cooling. Also, microstructure formations were investigated by X-ray and SEM analyses.Test results showed that the pumice mortar incorporating 60% fly ash revealed the best performance particularly at 900 °C. This mixture did not show any loss in compressive strength at all test temperatures when cooled in air. The superior performance of 60% FA mortar may be attributed to the strong aggregate–cement paste interfacial transition zone (ITZ) and ceramic bond formation at 900 °C. However, all mortar specimens showed severe losses in terms of flexural strength. Furthermore, specimens cooled in water showed greater strength loss than the air cooled specimens. Nevertheless, the developed pumice, fly ash and cement based mortars seemed to be a promising material in preventing high temperature hazards.
    Cement and Concrete Research. 01/2007;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The main objective of this study is to investigate the potential use of various solid wastes for producing construction materials. The paper is based on the comprehensive review of available literature on the construction materials including different kinds of solid wastes. The traditional methods for producing construction materials are using the valuable natural resources. Besides, the industrial and urban management systems are generating solid wastes, and most often dumping them in open fields. These activities pose serious detrimental effects on the environment. To safeguard the environment, many efforts are being made for the recycling of different types of solid wastes with a view to utilizing them in the production of various construction materials. This paper discusses the environmental implications caused by the generation of various solid wastes, and highlights their recycling potentials and possible use for producing construction materials. In addition, this paper shows the applications of solid waste based construction materials in real construction, and identifies the research needs.
    International Journal of the Physical Sciences. 11/2010; 5:1952-1963.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This research focuses on the possibility of constituting a more sustainable lightweight concrete, Mineralized Wood Concrete (MWC), substituting natural aggregates with wastes from woodworking activities. Exploiting this type of aggregates, a triple purpose has been achieved: preservation of natural raw materials, reuse of wastes and energy saving. Furthermore, the use of wood aggregates is a way to try to develop a sustainable concrete characterized by high thermal inertia, high thermal resistance and low weight.In this paper, effects of the addition of wood aggregates on mechanical and thermal properties of concrete are studied. Mechanical performances have been investigated with compressive strength tests, while a one-dimensional heat flow model has been used to predict the thermal conductivity of MWC.The use of MWC can be associated with the idea of a different typology of relatively heavy building envelope: this union could competitively answer to the demand of well-insulated building envelope and concurrently characterized by high thermal mass. From this union, a series of other values can be derived: low weight, environmentally friendly, easily industrialized and easy on-site casting. Consequently, applications of wood concrete in building constructions may be an interesting solution in order to improve sustainability and building energy efficiency.
    Energy and Buildings. 01/2009;