Several techniques exist to quantify the cementitious materials' degree of hydration, namely calorimetry, TG, and scanning electron microscopy [6, 7].In isothermal calorimetry technique, the early age hydration kinetics of the cement paste is evaluated by measuring the heat release rate of the samples at a constant temperature immediately …
Ordinary Portland cement (OPC) is the core ingredient of many construction materials. In 2022, 4.1 billion tons were used worldwide, contributing to ~8% of CO2 emissions ( ~ 3 Gt/year).
A commercial grade OPC (Type I/II) and CSA cement was received from Continental Cement Co. USA, and Buzzi Unicem USA, respectively. The elemental oxide composition of the cement samples was analyzed with Rigaku Supermini 200 wavelength dispersive X-ray fluorescence and presented in Table 1.The XRD profiles of the OPC …
Here, a hydration control additive can modify the kinetics of ordinary Portland cement to increase its strength, potentially reducing the amount of cement needed.
A model that describes hydration and heat-mass transport in Portland cement mortar during steam curing was developed. The hydration reactions are described by a maturity …
Ordinary Portland cement (OPC) hydration involves mechanisms of dissolution and precipitation in a complex chemical system composed of different mineral phases, …
Cement hydration is crucial for the strength development of cement-based materials; however, the mechanism that underlies this complex reaction remains poorly understood at the molecular level. An ...
DOI: 10.1016/j.jobe.2023.106120 Corpus ID: 256881494; Influence of polycarboxylate superplasticizer and calcium sulfoaluminate cement on the rheology, hydration kinetics, and porosity of portland cement pastes
The construction industry is consistently seeking innovative approaches to diminish carbon footprints by substituting ordinary Portland cement, which has a high carbon footprint, with alternative, low-carbon materials. Portland pozzolana cement, a blend of Portland cement and fly ash, can play a crucial role in the construction sector …
The study of the hydration reactions of Portland cement is well documented by conventional techniques such as X-ray diffraction, differential thermal and thermogravimetric analysis, or NMR, for …
The Portland cement hydration was monitored from the first minutes of hydration up to 28 days of curing. Measurements were started 10 min after the contact of the binder with deionized water. Temporal monitoring was performed at predetermined intervals: every 3 min during the first 2 h; every 10 min until completing 24 h of reaction, …
2.1 Materials. The cement used in the mortar specimens was a Mexican cement designated as CPO30RS. The oxide composition measured by X-ray fluorescence is shown in Table 1.The corresponding potential Bogue phase composition, heat of hydration and water necessary for cement hydration were calculated.
Hydration of Portland Cement. Concrete is prepared by mixing cement, water, and aggregate together to make a workable paste. It is molded or placed as desired, consolidated, and then left to harden. Concrete does not need to dry out in order to harden as commonly thought.
Cement mortar prisms were meticulously prepared in accordance with BS EN-196–1–2016 standards. As delineated in Table 3, a portion of the cement was substituted with LS powder at mass fractions of 5 % and 10 % and the weighed cement and limestone were poured into the mixer and mixed for 30 min, so that the powder was fully …
The interstitial solid material is best regarded as a coagulum resulting from the combination of low molecular mass silicate anions with dissolved calcium hydroxide. It is proposed that the low tensile strength of Portland cement paste results from microstructural features consequent upon this mechanism of hydration and setting.
1. Introduction. Water reducers are used for two purposes. They are either used to increase the dispersion of the cement grains and with that the workability of concrete and mortar or to reduce the water-to-cement ratio which results in a stronger and more durable product [1].Water reducers have usually no significant influence on the …
Finally, their effects on early hydration properties of Portland cement were preliminarily investigated by using isothermal calorimetry, XRD, TG and compressive strength tests. The experimental results showed that both SNS and CSNS with high dispersity and uniform size within 100 nm were successfully prepared. However, both of …
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 and distribution processes, helping members to continuously improve the nation's infrastructure and economy. ...
The hydration of Portland cement involves the reaction of the anhydrous calcium silicate and aluminate phases with water to form hydrated phases. These solid hydrates occupy more space than the anhydrous particles and the result is a rigid interlocking mass whose porosity is a function of the ratio of water to cement (w/c) in the original mix. ...
The hydration of commercial Portland cements and of synthetic Portland cement phases has been investigated, by electron optical methods and calorimetry. Examination of fracture surfaces in the scanning electron microscope (SEM), of ion-thinned sections from bulk pastes by transmission electron microscopy (TEM) and by scanning transmission …
This study investigates the influence of the replacement of 20% of Portland cement for silica fume (SF) or a 20-µm medium diameter quartz powder (QP) on the …
Lately, the investigations of binders from ternary system Portland cement (PC), calcium aluminate cement (CAC) and calcium sulfate ((Coverline S)), have gone through a larger stage of development due to their special properties such as fast setting and rapid hardening, early strength, non-efflorescence, etc.These special properties are …
The early-age hydration of Portland cement paste has an important impact on the formation of microstructure and development of strength. However, manual derivation of hydration kinetic equation is very difficult because there are multi-phased, multi-sized and interrelated complex chemical and physical reactions during cement …
Figure 1 illustrates the hydration process of Portland cement according to Le Chatelier's theory. Initially, the anhydrous clinker dissolves due to its higher solubility …
Determination of the degree of hydration of Portland cement using three different approaches: Scanning electron microscopy (SEM-BSE) and Thermogravimetric analysis (TGA). Case Studies in Construction Materials 2021, 15, e00754.
Mortar beams incorporating carbon nanofibers (CNFs), which were synthesized in situ on Portland cement particles, were used to produce nanomodified Portland cement sensors (SmartCem sensors). SmartCem sensors exhibited an electrical response comparable to a thermistor with a temperature coefficient of resistivity of − …
In this study, influence of different stone powders (SP), including limestone powders (LP), quartzite powders (QP), and granitic powders (GP), on the hydration behaviors of portland cement, for example, setting time, hydration heat, and hydration products, were discussed. The initial and the final setting time both shorten when the …
Understanding the role of natural pozzolana in regulating the early hydration reaction process and microstructure of Portland cement. Liyun Yi Department of ... (NP) on the early-age hydration process and microstructural development of Portland cement. Through a series of experiments, including low-field nuclear magnetic …
The effect of temperature, in the range 10–60°C, on the early hydration of two Portland cements from Mexico and three blended cements has been investigated by means of isothermal conduction calorimetry. The blended cements were based on the two Portland cements with partial replacement by ground granulated blast furnace slag, …
1. Introduction. Ordinary Portland cement (OPC) with mineral additions based on CaO, SO 3 and Al 2 O 3 are used in increasing amounts in both concrete practice and special applications [1].They are used as rapid setting cement with high early strength [2] or as shrinkage reducer [3].Many of the rapid hardening and expansive cements …
To understand the chemistry of Portland cement hydration, it is necessary to consider the hydration processes of the components of Portland cement clinker along …
Compatibility and hydration of Ordinary Portland Cement (OPC) with 15 commercially available tropical wood species were investigated by studying the heat release during cement hydration in various ...
Cement - Composition, Properties, Major Cements: Portland cement is made up of four main compounds: tricalcium silicate (3CaO · SiO2), dicalcium silicate (2CaO · SiO2), tricalcium aluminate (3CaO · Al2O3), and a tetra-calcium aluminoferrite (4CaO · Al2O3Fe2O3). In an abbreviated notation differing from the normal atomic symbols, …
The results show that the acrylic polymers SA and ACA significantly retars the setting and the hydration of portland cement. Addition of the VVC polymer, however, tends to accelerate the hydration of the cement. In addition, X-ray diffraction studies indicated that at the interface between the aggregates and the cement paste, calcium …
A The mechanism of cement hydration according to Le Chatelier: The dissolution of the anhydrous compounds ①is followed by precipitation of calcium silicate hydrate needles and hexagonal calcium hydroxide crystals from the supersaturated solution ②. The reduced ion concentration in the solution will restart the dissolution, and the …
A total of four different types of cements were used in this study: P·W 52.5 white cement from Aalborg Portland cement company (Anqing factory, Anhui, China); P·I 42.5 ordinary Portland cement (OPC, benchmark cement following China national standard GB8076-2008 for cement additive evaluation) from China United Cement …
α(t): Degree of hydration of the cement at time t. m sample: Mass of the samples. m c: Mass of the initial cement. ϒ 0: Amount of Ca(OH) 2 produced upon complete hydration of the cement. This value depends on the composition of the cement as well as the stoichiometry of the C-S-H gel of the cement hydration reactions (Eq.(1) …
The manufacture of portland cement contributes an estimated 5-8% of all anthropogenic carbon dioxide (CO2) emissions each year. One strategy to curb these cement-induced CO2 emissions is to reduce the amount of clinker in portland cement by replacing a portion with a widely available mineral filler, such as limestone. This research examines the …
Ordinary Portland cement (OPC) hydration involves mechanisms of dissolution and precipitation in a complex chemical system composed of different mineral phases, resulting in the formation of different hydrates. This leads to the setting and the hardening. The main objective of this chapter is to describe the fundamental steps that …
Presented within is a critical overview of the effect of sulfates on cement hydration, properties, and optimum sulfate content in Portland cement. Calcium sulfate …
