Showing papers in "Cement and Concrete Research in 1988"

TL;DR: In this article, the results of corrosion rate and simultaneous electrical resistance values of rebars in mortar fabricated with six different types of cements are given and the relation between those values is presented.

TL;DR: In this paper, a thermogravimetric test was conducted on hardened cement pastes containing fly ash and the results showed that the water content of these pastes can be divided into two components: water held by calcium hydroxide, and water held in other reaction products.

TL;DR: The major hydrate formed was struvite, NH4MgPO4·6H2O, usually accompanied by schertelite, at least initially as discussed by the authors.

TL;DR: In this paper, the alite/belite 29Si MAS NMR spectrum for white Portland cement has been used for quantitative analysis of synthetic and natural cement minerals and for following the hydration of white Portland Cement.

TL;DR: In this article, different cement pastes and concrete mixes were prepared using ordinary Portland cement and subjected to sulphuric acid attack and the main parameters investigated included w/c ratio and cement content.

TL;DR: In this article, the effects of chemical attack on portland cement mortar from internal and external sulfate sources were compared with respect to expansion and strength development and substantial differences exist between the two types of sulfate attack.

TL;DR: In this paper, the porosity of plain Portland cement pastes and those containing silica fume or fly ash was assessed by several methods on plain and blended Portland Cement pastes.

TL;DR: In this paper, concrete mixes of widely differing water/cement ratios were made using palm kernel shell as course aggregate, and the properties tested include the physical properties of the shell, the compressive, flexural and tensile splitting strengths of the concrete.

TL;DR: In this article, a review of the rheology of fresh cement pastes is presented, and comments on the analysis of experimental data are made on the correlation between the pastes and the experimental data.

TL;DR: In this article, the authors investigated the mechanism of Co 2+ and Ni 2+ replacement of Ca 2+ by the breakdown of structural CaO bonds and appears to take place from edge to core in these minerals.

TL;DR: In this paper, the influence of mechanical loading effects on carbonation or chloride penetration is studied in reinforced concrete beams of 3 m long which are stored in a mechanical loading state and in aggressive environments.

TL;DR: In this article, the authors used an instrumented drop-weight impact machine to drop a 345 kg mass from a height of 0.5 m to a clear span of 960 mm.

TL;DR: In this article, the NBRI accelerated test was used to investigate whether it mimics the natural alkali-silica reaction in concrete and mortar specimens, and the results showed that the reaction products were very similar to those found in structures affected by the reaction in the field.

TL;DR: In this article, the results of accelerated tests carried out to investigate the effects of using different curing regimes on the rate of concrete carbonation were discussed, and the results indicated that the carbonation rate of prisms cured in water for 28 days was only 17% of that for prists cured in air for the same period of time.

TL;DR: The impact of blending agents on the internal environment of cement systems is assessed by chemical analysis of the pore fluid in cured blends in this article, which shows that the short-term behaviour of PFA blends is complicated by the presence of soluble alkali.

TL;DR: In this paper, the effect of molecular weight of a superplasticizer on the adsorption on cement was investigated by microelectrophoresis and UV-absorption techniques.

TL;DR: In this article, the authors have reported different aspects of a long term study on the marine durability of steel fibre reinforced concrete (sfrc) two mixes, one with and one without pfa were reinforced with three types of steel fibres The cement content of the mixes was 430 and 590 kg/m3 respectively and specimens of these mixes were cured under marine exposure, both in the laboratory and at Aberdeen beach, for up to 2000 wet-dry cycles (1200 days).

TL;DR: In this article, the effect of fly ash on the compressive strength development of the hardened concrete was evaluated, and it was concluded that the use of a large amount of fly-ash, as replacement for both cement and sand, is highly beneficial.

TL;DR: In this paper, the effects of three drying procedures, namely oven-drying, sublimation and sublimations followed by oven drying, on the pore structure of cement pastes were studied.

TL;DR: The chemistry of hydration of monocalcium aluminate, CA, has been studied at several temperatures using conduction calorimetry, X-ray diffraction and other techniques as discussed by the authors.

TL;DR: An analytical study of hydrochloric acid attack on cement mortar prisms is done in this paper, where 4×4×16 cm morter prism specimens (cement sand ratio 1:3) were made.

TL;DR: In this paper, the authors used selective dissolution, TG, XRD, analytical electron microscopy and Ca(OH)2 determinations on both whole samples and dissolution residues to determine changes in the mineralogy of Portland cements.

TL;DR: In this paper, an assessment of the nature of the components of pulverized-fuel ash (pfa) has shown a dominance of hollow, glassy spheres with a composite shell.

TL;DR: In this article, a new theory for the basic creep of concrete which takes aging into account in a manner which is better justified physically, better agrees with test results, and is more efficient computationally is presented.

TL;DR: In this article, the relative vapour pressures of sulphates important to cement clinkering have been measured using the Knudsen effusion cell technique and with the aid of a simplified model of circulation in the kiln, some features of the oxidized sulphur cycle are interpreted.

TL;DR: In this paper, a 0,25 water-cement ratio concrete with various air void spacing factors was tested for freezethaw durability in accordance with ASTM Standard C 666 (procedure A) and for deicer salt scaling resistance.

TL;DR: In this article, the hydration behavior of C2A7, a component of many calcium aluminate cements, has been studied over a range of temperature using conduction calorimetry, X-ray and thermal analysis techniques.

TL;DR: In this article, a mathematical model for the kinetics of hydration of tricalcium aluminate in the presence of gypsum was developed, and the model was solved, illustrated and compared to experimental heat release data.

TL;DR: In this paper, the authors clarified the characters of impurities in phosphogypsum produced in Turkey and to obtain refined phosphogypum using various methods following IR technique, which can improve the hydration of trass cement.

TL;DR: The stereological method of total projection was practically not applied yet because of the difficulty to use it manually as mentioned in this paper. Yet, determinist, it is more precise than the oriented secants technique which is statistic.