C 3 A is the fastest hydrated mineral in ordinary Portland cement. Fig. 2 shows the hydration heat of Portland cement slurry with and without alkanolamine. It can be seen that in the first few minutes, alkanolamine accelerated the hydration of C 3 A (peak 1). Yaphary et al. [37] attributed the enhanced hydration of C 3 A to the chelation of …
T able 3—Effect of mixing time on setting time of . ... [29][30][31]. Struble and Lei [24] reported that the rapid increase in yield stress indicates initial setting of a Portland cement mortar. ...
Glycerin has been an important component of grinding aids and set retarders commonly used in cement industry for a long time [18], [19]. Some research has been done by global scholars, but most of their work focuses on the grinding effect and retarding effect of glycerin or glycerol-based grinding aids on blended cement [12], …
Portland cement CEM I is obtained from (95–97%) of clinker and (3–5%) of gypsum, according to EN 197-1 (2011) standard. Sulfur xide SO 3 is the main component of gypsum (Calcium Sulfate Dihydrate CaSO 4 ·2H 2 O), it may also originate from clinker, the previous standard has limited its content in cement at 4%. It is known …
In this study limestone powders with different particle sizes of 5, 10 and 20 μm were used to replace a part of Portland cement in different replacement levels to produce Portland-limestone cement pastes. The percentages of limestone replacement are 0, 5, 7.5, 10, 12.5, 15 and 20% by weight. The effect of fineness and the amount of …
P·O 42.5 ordinary Portland cement (OPC) is selected, with a specific gravity and specific surface area of 3.16 g/cm 3 and 354 m 2 /kg, respectively. The chemical composition of cement is shown in Table 1. Diammonium hydrogen phosphate (DAP) is chemically pure with a purity greater than 99 %. ... In this study, the effect of DAP on the …
Such effect was mainly achieved via the combination of TEA 19,20,21 and glycerol, which was known to be able to accelerate the aluminate reaction …
Mechanism of Sulfate Attack Hydration of Portland Cement C~A hydrates the most rapidly, followed by the iron compound C.AF, th~en C~S and C,S. The stiffening and setting characteristics of 4 J portland cement paste largely determined by the hydration reactions ate involving aluminates.
The effect of glycerin on viscosity is more obvious at larger shear rates. ... To maintain the long-term integrity of the set cement, design of mechanical properties like young's modulus, poisson's ratio, compressive strength, tensile strength etc. are extremely significant. ... Leaching of Portland cement has also been observed due to ...
Conclusions: Addition of 15% glycerin to Portland cement has improved the setting time, the cohesiveness and the anti-washout ability of the cement with subsequent improvement …
DOI: 10.1016/j.conbuildmat.2022.126554 Corpus ID: 246311896; Acceleration of cement hydration – A review of the working mechanisms, effects on setting time, and compressive strength development of accelerating admixtures
The feasibility of modified glycerol distillation residues (MGDR) used for chemical additives of cement was studied. MGDR showed good grinding and strengthen effect which was similar with ...
production of Portland cement, grinding aids are added in small amounts in the range of 0.01 to 0.10% by weight of cement, according to the PN-EN 197-1 standard [ 1
1. Introduction. Manufacturing of Portland cement consumes huge amount of energy and raw materials and at the same time emits lot of CO 2 responsible for global warming [1].Global annual cement production is expected to be 5.9 billion tons with more than 4.8 billion tons CO 2 production by 2020. This situation will be alarming and hence …
The Portland Cement Association is the premier organization serving America's cement manufacturers. With a focus on safety and sustainability, we support innovative approaches at every stage of the manufacturing …
The study investigated the effect of keratin fibers from waste chicken feather on the hydration characteristics of Type I Portland cement. The effect of varying amount of fibers on cement setting ...
This effect of compounds with boron is also known from other studies. For example, Kratochvíl et al. [25] have studied how additions of different boron compounds (up to 2% of the cement mass ...
Objective: The purpose of this study was to investigate the effects of polycaboxylate superplasticizer on setting time and flowability of white Portland cement without gypsum in order to improve ...
The effect of ethanolamines—monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA)—on the hydration, mechanical and surface properties of the white Portland cement pastes (white ...
Conclusions: Addition of 15% glycerin to Portland cement has improved the setting time, the cohesiveness and the anti-washout ability of the cement with subsequent …
DURING an investigation of the retardation of setting in Portland cement pastes by a series of sugars, the disaccharide αα-trehalose was found to possess only weak retarding properties, while all the other sugars studied were powerful set-retarding agents. The reason for the distinctive behaviour of αα-trehalose may help to explain the mechanisms …
In this context, this study aimed to evaluate the effect of crude glycerin as an admixture on the hydration of cement paste based on infrared absorption …
Conclusions: Addition of 15% glycerin to Portland cement has improved the setting time, the cohesiveness and the anti-washout ability of the cement with …
erating effect was dependent on the aluminate content of the cement. This assumption was not verified for cements at low temperature (5 C). The results obtained showed that calcium nitrate does function as a set accelerator for cement between 7 and 20 C, but that the set accelerat-ing efficiency of calcium nitrate depends very much on cement ...
Setting time of cement is same as setting time of concrete. Stages of setting of cement, setting times of cement and factors affecting and initial and final setting time of different cements and various processes …
MPC could be used rapid repair material for Portland cement concrete structures due to several advantages: fast setting and hardening (Qiao et al., 2010 (Qiao et al.,, F. 2009) (even at ...
This study aims to analyze the effects of supercritical carbonation (CO2 at 20 MPa and 318 K) on the physicochemical properties of ordinary Portland cement pastes. The evolution of the main crystalline phases of the cement pastes during carbonation was determined by means of X-ray diffraction and thermogravimetric analysis. The pore …
Calcium sulfoaluminate cement (CSAB) is an environmentally friendly alternative to Portland cement (PC) (Chaunsali and Vaishnav 2020; Gartner 2004; Gartner and Sui 2018).The amount of carbon dioxide (CO 2) released in the manufacturing of CSAB cement is about 30% lower than that for PC (Hanein et al. 2018; Zhou et al. 2006).The …
Abstract. The influence of grinding aids (pure triethanolamine and ethylene glycol) on the properties of cements, their compatibility with an acrylate-based superplasticizer and the rheological parameters of …
The strength of cement and its setting time will decrease significantly, if the content of BaO in clinker is high (about 47%). ... Speciments of concrete mortar were prepared using a mix of ...
Cement Clinker The alcohol-glycerol method (8) has been used in this laboratory for many years for determining free lime in Portland cement and in preparations of silicates and aluminates of calcium. In the present study no extended work with commercial cements was undertaken. For comparison, two cements were used, one a dark-colored ...
