2026-09-21T08:13:23Zhttps://bura.brunel.ac.uk/oai/request

oai:bura.brunel.ac.uk:2438/48832014-11-01T11:25:15Zcom_2438_58com_2438_23col_2438_4327col_2438_3672

Sing, KSW Yates, Malcolm 2011-03-25T15:51:00Z 2011-03-25T15:51:00Z 1991 http://bura.brunel.ac.uk/handle/2438/4883 This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University. The present study deals with the physical characterization of macrodefect free cements produced by ICI. These materials are made through a specialized mixing technique which incorporates an organic polymer into the cement/water system. The high mechanical strength and low porosity of this class of hardened cement paste had been well documented, however, a detailed characterization of the physical nature of the microstructure had not previously been attempted. Two classes of macrodefect free material were studied, based on Ordinary Portland cement and High Alumina cement, respectively. The porosities of these two materials were determined in their original state and after various forms of heat treatment and conditioning. Samples based on Ordinary Portland cement had a well defined narrow pore size distribution, even after heat treatment, while the High Alumina cement samples displayed a very low total pore volume in their original state, but subsequent heat treatment led to the developement of porosity over a wide range of pore sizes. These fundamental differences in the pore size distributions had significant effects on the homogeneity and reproducibility of the microstructures of the samples. The porosity generated by heat treatment was found to be unstable in the presence of water. In general, reductions in the porosities and permeabilities were observed. This was due to the formation of fresh cement hydrate gel within the pore structure, which caused a shift in the pore size distributions towards smaller pores. Submitted by Otue Ekong (lbsrooe@brunel.ac.uk) on 2011-03-25T15:50:36Z No. of bitstreams: 1 FulltextThesis.pdf: 10155642 bytes, checksum: dc919120a0c7b514e73530b9ddf4f2e8 (MD5) Approved for entry into archive by Otue Ekong(lbsrooe@brunel.ac.uk) on 2011-03-25T15:51:00Z (GMT) No. of bitstreams: 1 FulltextThesis.pdf: 10155642 bytes, checksum: dc919120a0c7b514e73530b9ddf4f2e8 (MD5) Made available in DSpace on 2011-03-25T15:51:00Z (GMT). No. of bitstreams: 1 FulltextThesis.pdf: 10155642 bytes, checksum: dc919120a0c7b514e73530b9ddf4f2e8 (MD5) British Gas; ICI en http://bura.brunel.ac.uk/bitstream/2438/4883/1/FulltextThesis.pdf Macrodefect free cement Cement porosity Cement permeability Hydrate gel Pore size distribution The characterization of novel cements Thesis