Showing papers in "Cement and Concrete Research in 1978"

TL;DR: The character of the liquid phase in contact with hydrating portland cement is significantly affected by the presence of alkalies as discussed by the authors and the effects of increased alkali contents on the hydration processes are manifested in the engineering properties of cement pastes and concretes produced from it.

TL;DR: The morphology of the contact zone developed between Portland cement paste and glass slide "aggregates" has been explored using SEM and other techniques as mentioned in this paper, where a duplex film of about 1 μm total thickness is rapidly deposited on the glass surface.

TL;DR: In this article, the influence of Ca(OH) 2, CaSO 4 ·2H 2 O and Na 2 SO 4 on the C 3 A hydration was examined in order to study the retardation mechanism caused by lime and/or gypsum additions.

TL;DR: In this article, the authors used X-ray diffraction and microscopic study of reacted solids to show that C 3 A. O forms at all temperatures and at temperatures below about 20°C complex salts containing CaCl 2, Ca(OH) 2 and/or CaCO 3 crystallalise out if the CaCl2 concentration of the mother liquor is 15% or higher.

TL;DR: In this article, C3S pastes hydrated at 25°C have been studied using QXRD, TG and trimethylsilylation to determine determinemonomeric and dimeric silicate.

TL;DR: In this paper, the authors made measurements of elasticity and microhardness on magnesium oxysulfate systems (paste and compacted) having a wide range of porosity.

TL;DR: The effect of superplasticizing admixtures upon the rheological properties of cement pastes, mortars and slurries has been investigated by a number of methods, including: zeta potential (by electrophoresis and streaming potential), capillary rise, adsorption isotherm measurements, flow table tests and rotational viscometer studies as mentioned in this paper.

TL;DR: In this paper, porous particles with at least 30 per cent total porosity and pore diameters, mainly between 0.3 and 2 microns, added to the plastic mix were found to improve significantly the freeze-thaw resistance of hydrated neat cement paste and concrete.

TL;DR: In this article, an accelerated test method was proposed for the detection of potential alkali-aggregate reactivities of aggregates, which consists of making 1:3 sand cement mortar prisms and placing the prisms in a saturated NaCl solution at 50°C.

TL;DR: In this paper, it was shown that C2ASH8 has strength giving properties and that it can give a significant increase in strength using Commercial HAC and prehydrated ordinary Portland cement.

TL;DR: In this paper, the authors describe a study of the structure, composition and strength of cement paste near the cement-steel interface of an embedded wire and show that the interface does not change appreciably for curing times greater than a week and suggests enrichment of the interface with Ca(OH)2 X-ray diffraction.

TL;DR: In this paper, a mixture of lime, colloidal silica and quartz was treated hydrothermally in stirred suspensions at 180°C to prepare 11 A tobermorite with Ca/Si = 0.8.

TL;DR: In this paper, the existence of hollow-shell or Hadley grains in bulk cement paste specimens has been investigated and it was found that almost all fractured grains observed seem to be of the hollowshell variety, similar to those previously established as occurring near interfaces with glass slides.

TL;DR: In this paper, surface areas, total pore volumes and the microstructure of the hardened expansive cement pastes are discussed, and the results obtained are compared with each other using scanning electron microscopy.

TL;DR: In this article, B 2 O 3 -stabilized α′- and β-C 2 S-polymorphs were determined using electron microscopy and electron diffraction at reaction times between 5 hours and 28 days.

TL;DR: In this article, it was found that ddg-dicalcium silicate was hydraulic, but much less so than the β-variety, and a similar type of calcium silicate hydrate was produced.

TL;DR: The polymorphism of Ca3SiO5 has been studied microscopically by following changes in optic properties and modes of twinning of the crystal as a function of temperature.

TL;DR: In this article, Setter et al. discuss the importance of the setter setter algorithm and its application in the context of cancer detection.Reference: Setter, N Penn State Univ,Mat Res Lab,University Pk,Pa 16802Fs738Times Cited:10Cited References Count:0 Reference LC-ARTICLE-1978-002

TL;DR: In this article, structural changes occurring during creep and shrinkage of pure calcium silicate pastes were investigated, including determination of pore structure and surface area by adsorption of H 2 O and N 2.

TL;DR: In this article, a series of articles dealing with the creep and shrinkage of calcium silicate pastes is presented, including materials, specimen preparation methods, mechanical test procedures and results.

TL;DR: In this paper, the chemistry of the clinker minerals was studied with the electron microprobe; the alites and belites could be easily determined but the aluminates and ferrites were difficult or impossible to determine separately.

TL;DR: In this paper, the compressive strength of concrete is shown to be increased by the presence of sodium chloride or ocean salts in the mixing water, and the strength was found to increase with increasing salinity even up to 7% by weight of water.

TL;DR: In this article, a study of the processes involved at and near the steel-matrix interface when an embedded steel wire is pulled out of a cement paste or mortar matrix is presented.

TL;DR: In this article, the authors studied the kinetics of hydrothermal reactions for mixtures of CaO and quartz with Ca/Si = 0.8 and 1.0 in stirred suspensions at 120 − 180°C.

TL;DR: In this paper, the water is assumed to be present in the structure and the formula is Ca 5 SiO 4 ) 2 SO 11.88 (OH) 0.24.

TL;DR: In this paper, a non-destructive method is presented to study the combining properties of a number of hardened cement pastes for NaCl and CaCl 2, and the dependence of the amount of chloride combined by the cement on the total amount added to the cement is calculated.

TL;DR: In this article, the hydration kinetics of synthetic alites bearing Al, Fe, Mg and Mg have been analyzed using X-ray diffraction and scanning electron microscopy.

TL;DR: In this article, the authors studied the mechanism of reactions in the zeolitic tuff-CaOH 2 O systems at increased temperature by means of X-ray diffraction and SEM.

TL;DR: Sodium lignosulfonate in combination with sodium carbonate controls the setting of pure portland clinker pastes and exhibits a strong liquefying effect on both pure clinker and cement pastes as mentioned in this paper.