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Showing papers in "Cement and Concrete Research in 2001"


Journal ArticleDOI
TL;DR: In this paper, performance tests have been carried out for fresh and hardened properties of concrete made with commercially produced coarse recycled concrete aggregate and natural fine sand, and the results indicate that the difference between the characteristics of fresh-and hardened recycled aggregate concrete and natural aggregate concrete is perhaps relatively narrow than reported for laboratory-crushed recycled aggregatecrete mixtures.

638 citations


Journal ArticleDOI
TL;DR: In this article, chemical and microstructural aspects of delayed ettringite formation are reviewed, and the authors show that the rate and ultimate extent of expansion are influenced by factors of three types: chemistry, paste microstructure, which determines the stresses produced by its formation.

611 citations


Journal ArticleDOI
TL;DR: In this article, the role of fibres is discussed through the analysis of concrete microstructure and fibre-matrix interactions as function of heat treatment, and the authors show that the presence of polypropylene fibres led to a large decrease in the extent of the pressure fields that build up in the porous network during heating.

587 citations


Journal ArticleDOI
TL;DR: In this paper, the effects of four drying methods (oven-drying at 60°C and 105°C, vacuum-dough, and freeze-decompensation) on porosity and pore structure determined by MIP, were compared.

568 citations


Journal ArticleDOI
TL;DR: In this paper, a new mix design method for self-compacting concrete (SCC) is proposed, where the amount of aggregates required is determined, and the paste of binders is then filled into the voids of aggregate to ensure that the concrete thus obtained has flowability, selfcompacting ability and other desired SCC properties.

568 citations


Journal ArticleDOI
TL;DR: In this paper, rheological tests on cement paste were used to successfully select the type and dosage of mineral admixtures that improved concrete workability, and the conclusion reached based on the cement paste tests were validated by concrete slump tests.

561 citations


Journal ArticleDOI
TL;DR: In this article, the chemistry and physics of sulfoaluminate cements hydration are described, and it is concluded that the self-desiccated state, once achieved, is very difficult to resaturate and that the dry internal environment is partly responsible for the virtual absence of corrosion of embedded steel.

508 citations


Journal ArticleDOI
TL;DR: In this paper, the properties of Portland cements (C3S and alite, C2S, C3A, C4AF) were measured at the microscopic scale by nanoindentation and at the macroscopic scale by the resonance frequencies technique.

453 citations


Journal ArticleDOI
TL;DR: In this paper, the initial results of an experimental program aimed at producing and evaluating self-compacting concrete (SCC) made with high-volumes of fly ash are presented and discussed.

449 citations


Journal ArticleDOI
TL;DR: In this paper, a partial replacement of normal-weight aggregate by saturated lightweight aggregate was shown to be effective in eliminating the autogenous shrinkage and restrained stresses of the normal weight concrete.

422 citations


Journal ArticleDOI
TL;DR: In this paper, a study about the hydration of pure C3A phase with CaCO3 in the presence or not of gypsum and in a calcium hydroxide solution is related to hydration products of portland and limestone-blended cements.

Journal ArticleDOI
TL;DR: In this paper, the strength and durability performance of normal and high-strength pozzolanic concretes incorporating silica fume, fly ash, and blast furnace slag was compared at elevated temperatures up to 800°C.

Journal ArticleDOI
TL;DR: In this article, the authors propose three categories to describe the interactions and state of the superplasticizers with the cement suspensions, i.e., intercalation, coprecipitation or micellization.

Journal ArticleDOI
TL;DR: In this paper, the hydration progress in metakaolin-blended high-performance cement pastes with age was assessed from the measurements of compressive strength, porosity, and pore size distribution, the degree of pozzolanic reaction, and the Ca(OH)2(CH) content of the MK-blending pastes at a water-to-binder ratio of 0.3.

Journal ArticleDOI
TL;DR: In this paper, the change of specific surface area and pore size distribution due to carbonation of an ordinary Portland cement mortar was investigated, where the adsorption of water vapor on noncarbonated and well-carbonated cement mortar is measured in order to evaluate the difference in specific surface areas for the two samples using the BET theory.

Journal ArticleDOI
TL;DR: An overview of autogenous deformation and change of the relative humidity (RH-change) can be found in this article, where an overview of the current status of this research field is given.

Journal ArticleDOI
TL;DR: In this article, the compressive strength of concretes cured under sealed conditions was investigated and it was shown that up to 67% of the concrete could be replaced without any significant reductions in strength.

Journal ArticleDOI
TL;DR: In this article, the decomposition and reformation of ettringite is studied as a function of water vapour pressure and temperature, and the authors make recommendations for the upper safe service limits for ETTringite-based cements.

Journal ArticleDOI
TL;DR: In this paper, the active control of the sulfate ion concentration in aqueous phase by adding soluble salts containing multiple-charged cations, such as CaCl 2 and alkaline sulfate, has been attempted.

Journal ArticleDOI
Bertil Persson1
TL;DR: An experimental and numerical study on mechanical properties, such as strength, elastic modulus, creep and shrinkage, of Self-Compacting Concrete, SCC, and the corresponding properties of Normal Compacting concrete, NC, is outlined in this paper.

Journal ArticleDOI
TL;DR: In this paper, the role of the cation in the sulfate solution, and the effects of formation of various products like gypsum, ettringite, and thaumasite, on the extent of damage need to be investigated.

Journal ArticleDOI
TL;DR: In this paper, a series of metakaolin mixes were activated in 1:1 proportion, with different sodium hydroxide concentrations: 5, 10, 12, 15 and 18 M at 45°C during 24 hours.

Journal ArticleDOI
TL;DR: In this article, a blend of blended cements with 30% and 50% slag and water:solids ratios (w/s) of 0.50 and 0.35, respectively, were used for up to 6 months.

Journal ArticleDOI
TL;DR: In this article, the early-age desiccation of cement-based materials with and without a shrinkage-reducing admixture (SRA) have been performed under both sealed and drying conditions.

Journal ArticleDOI
TL;DR: In this article, the authors investigated the effects of replacing large volumes of cement with both classified and unclassified fly ash on the properties of foamed concrete and found that water vapour permeability increased with increasing porosity and ash content.

Journal ArticleDOI
TL;DR: In this article, the development of microstructure and compressive strength of three blended cement pastes hydrated at temperatures ranging from 10°C to 60°C was described; the replacement materials were pulverised fuel ash (PFA), volcanic ash (VA), and ground, granulated blast furnace slag (GGBFS), and blended cements had the same compositions as those reported in previous studies.

Journal ArticleDOI
TL;DR: In this article, the effect of hybrid fibers and/or expansive agent on the shrinkage and water permeation properties of high performance concrete (HPC) was investigated, and the results indicated that the hybrid fibers of different types and sizes could reduce the size and amount of crack source at different scales.

Journal ArticleDOI
TL;DR: In this paper, the properties of two commercially produced belite-sulfoaluminate-based cements have been studied, and they show rapid strength development and excellent sulfate resistance.

Journal ArticleDOI
TL;DR: In this paper, a new method to estimate yield stress of high-performance, pseudoplastic grouts is proposed and shown to result in lower yield stress estimates than the other models.

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the durability of AAS concrete exposed to carbonation and found that AAScrete had higher strength loss and depth of carbonation than OPC concrete.