However, Chen [19] reported the volume expansion rates of cement paste increased gradually with the addition of CFA content (greater than25 wt%). Besides, frost resistance, corrosion resistance, ... It is apparent from Fig. 11 that the main minerals of CCM40 were SiO 2, ettringite, amorphous minerals, gypsum, Ca(OH) 2, and f-CaO. It …Web

existence of gypsum in the soil and its soluble characteristics. The soil which contains gypsum is termed as Gypseous soil or gypsiferous soil [10]. The gypsum is extended to around 1/5th of land in the world [39]. In India, gypseous soil covers 0.06% of the total area of India i.e. it is extended over an area of 182.0 km2, [10, 40].Web

Both expansion effect and compressive strength of samples blended with GGBS were increased by gypsum, because of the gypsum promoted the generation of AFt and stimulated the hydration of GGBS.Web

The investigation aims to check the effect of variation of gypsum and water content on the engineering properties of expansive soil by different experiments, namely, mini compaction test, Atterberg limit's test, and unconfined compressive strength test along with microstructural analysis. The effect of gypsum (0%, 2%, 4%, 6%, 8%, and 10%), …Web

Ettringite is the mineral name for calcium sulfoaluminate (3CaO•Al 2 O 3 •3CaSO 4 •32H 2 ... expansion of deteriorating concrete. ... intergrinding the Type I cement with additional gypsum (SO 3 =3.14%) to increase the amount of available sulfate in the concrete. Concrete prisms made from these cements wereWeb

The expansion rate of samples basically has the same tendency in simulated mass concrete environment, whether mineral admixtures added or not (Fig. 1(a and b)). ... the effects of two mineral admixtures (GGBS and FA) and adding gypsum on the expansion performance of expansive agent at the simulated mass concrete …Web

DOI: 10.1016/j.jobe.2023.106288 Corpus ID: 257529776; Hydration and mechanical properties of FGD gypsum-cement-mineral powder composites @article{Gou2023HydrationAM, title={Hydration and mechanical properties of FGD gypsum-cement-mineral powder composites}, author={Mifeng Gou and Mengke Zhao …Web

Hydration. Expansion. Gypsum. Sulfoaluminate. 1. Introduction. The behavior of CSA-based cements is mainly regulated by ettringite, Ca 6 [Al (OH) 6] 2 (SO 4) 3 26H 2O or (according to the cement chemistry short notation) C 6 A S ‾ 3 H 32, produced upon hydration of their key-component, C 4 A 3 S ‾.Web

Yu et al. [ 10] found that the changes in the microstructure of gypsum crystals in different concentrations of salt solution seriously affected its physical and mechanical properties, especially permeability, extreme strength, and deformation characteristics. Evju et al. [ 11] studied the growth and expansion of anhydrite in solution …Web

It counteracts the tendency of some cement compounds to cause excessive expansion and cracking, promoting dimensional stability in the hardened concrete. Effects of Gypsum on Cement Improved Workability. Gypsum enhances the flowability and plasticity of cement, making it easier to pour, mould, and shape.Web

only gypsum as a binder or overwhelmingly rely on gypsum as a binder relative to other binders. Distress from Grout expansion given adequate gypsum and portland cement content as well as exposure to moisture, internal volumetric expansion of post pocket grout can occur long after the grout's initial set. the expansion causesWeb

Table 5, Table 6, Table 7 showed composition ratio of the samples. The reference sample was composed of Portland cement. The samples of A system were composed of 90% Portland cement and 10% mixed binder of FGD gypsum and aluminate cement.The samples of B system were composed of 80% Portland cement and 20% …Web

The expansion of MgO concrete is the result of the combined action of the expansion source and the environment in which it is located. Approximately 117% of molar solid volume increase relies on the hydration of MgO to Mg (OH) 2, but the expansion of MgO concrete is not equal to the expansion of MgO.Web

This white paper reveals the misconceptions and inherent features and benefits of gypsum cement by exploring the basic science behind it. ... By definition, gypsum is a "mineral of crystalline structure composed of calcium (Ca), sulfate (SO ... cement (PC) and calcium aluminate cement (CAC)). 2. As expansion occurs, the mass finds every nook ...Web

The test method involves the measurement of expansion of mortar bars made from a combination of Portland cement and gypsum. The gypsum increases the amount of ettringite produced in the fresh and hardened concrete and accelerates the reactions typical of sulfate attack. ... 0.06% expansion at 14 days for moderate sulfate-resistant Type II ...Web

Abstract. Sulfate attack on Portland cement concrete is often said to arise from each of two major sulfate reactions: (1) The sulfate ions react with C{sub 3}A and its hydration products to form ettringite with an increase in volume that results in expansion and subsequent cracking of the concrete; (2) The sulfate ions react with calcium …Web

NEWARK, Del, March 21, 2023 (GLOBE NEWSWIRE) -- Gypsum sales are estimated to reach US$ 7.85 billion in 2023. By 2033, the market may register a 6.2% CAGR, reaching US$ 13.76 billion.Web

Experimental results show that when the gypsum was added in the three kinds of cementitious system, water consumption of standard consistence decreased …Web

No matter of pure cement group, cement + gypsum group or high-resistance sulfate cement + gypsum group, the change of expansion rate after 210 d was consistent with PC > > F30 ≈ F20M10 > F25M5. ... Long-term hydrochemical corrosion leads to mineral dissolution, meso-structure change, and further mechanical deterioration of rock. ...Web

3.2 Unrestrained deformation. Figure 2 shows the influence of fly ash type and gypsum addition on early-age expansion behavior of OPC–CSA blends, respectively. The main difference between the two types of fly ashes (FFA and CFA) was reflected in the duration and magnitude of expansion. The expansion ceased earlier in …Web

No matter of pure cement group, cement + gypsum group or high-resistance sulfate cement + gypsum group, the change of expansion rate after 210 d was …Web

The expansion of low heat Portland slag cement with slight expansion (LSE cement) was studied by XRD, SEM and test methods for strength and expansion. Results indicated that under the condition of 4.5–5.0% MgO in clinker and 2.8–3.4% SO 3 in cement, ettringite expansion and brucite expansion produced by periclase hydration in …Web

The article analyzes the influence of material composition of modified gypsum-alumina expanding cement with regard to mineral components ratio on its …Web

This is typical of cement and gypsum plaster hydration, etc., but also of a wide range of geochemical processes such as the weathering of rocks, hydrothermal mineral transformations, etc. One might even consider it to include the corrosion of metals in water, although of course that type of reaction also has a strong redox component …Web

Section snippets Materials. Natural river sand (0–4 mm) and commercial quartz sand (0.6–1.2 mm and 1.2–2.5 mm) with a specific gravity of 2.66 and 2.65, respectively were used as fine aggregates.The natural crushed gypsum with the SO 3 content of nearly 38% was used as a partial substitution of the natural river sand to raise …Web

One of the key elements driving the gypsum mineral market's growth is the expansion of the building sector. Gypsum sales are estimated to reach US$ 7.85 billion in 2023. By 2033, the market may ...Web

This paper aims to study the effects of gypsum type and dosage on the rheological and strength properties of steel-slag cemented paste backfill (SSB-CPB) using fluorogypsum (FG), phosphogypsum (PG), and desulfurization gypsum (DG). Experimental results indicate that the yield stress and the viscosity of fresh SSB-CPB are the smallest …Web

The proportions of the mixtures are gypsum—70%, cement—15%, mineral additive—15%. The amount of superplasticizer 1% by weight of the mix. The amount of water was selected for each composition individually, taking into account the achievement of a …Web

The results show that the best conditions for gypsum-bauxite grouting mortar are as follows: a water-to-binder ratio of 0.3, a mineral admixture content of ~15%, and a molar ratio K of 2. The ultimate …Web

Calcium-based binders, such as ordinary Portland cement (OPC) and lime (CaO), are the most common artificial cementitious materials used worldwide for concrete and soil improvement. However, using cement and lime has become one of the main concerns for engineers because they negatively affect the environment and economy, …Web

Special Issue "Cement, Gypsum, and Lime Composites: Methods, Models, Kinetics, and Recent Advances" ... the use of L-GGBS combination was found to be effective in ameliorating sulphate-induced expansion and therefore encouraged in the stabilisation of subgrade and road-base materials with high sulphate contents. ... Mineral analyses …Web

The effect of gypsum additions on the physical performance of lime-stabilized kaolinite has been determined. Kaolinite containing different amounts of lime (i.e. 6 and 14 wt%) and gypsum (i.e. 2,4,6 and 8 wt%) was compacted into cylinders and moist cured at 30°C and r.h. for periods from 2 days up to 20 weeks.Web

Role of Gypsum in Cement. The main purpose of adding gypsum in the cement is to slow down the hydration process of cement once it is …Web

This results in the formation of expansive products such as gypsum and ettringite filling pores, which can lead to the expansion of cement-based materials and microcracks [6,7]. The associated leaching phenomenon in an acid solution leads mainly to the dissolution of portlandite (CH) and the decalcification of calcium silicate hydrates ( C …Web

In mass concrete, shrinkage resulting from temperature drop and drying leads to cracking, which can seriously affect the strength and durability of cement-based materials. Fortunately, expansion agents can deter or prevent these effects, especially MgO expansion agents (MEAs). In this study, the effects of four MEAs of different activity …Web

Gypsum Supergroup. Name: First known mention is by Theophrastus about 300-325 BCE from the Greek γυψοζ (gypsos) meaning plaster. Isostructural with: Ardealite, Brushite, Pharmacolite. The most common sulphate mineral. Found as both massive material, including the alabaster variety; and clear crystals, the selenite variety; and, parallel ...Web

Gypsum is a versatile mineral widely used in various industries. It is primarily known for its use in the construction sector as a key component in drywall, plaster, and cement. Gypsum offers exceptional fire resistance, sound insulation, and moisture control properties. Additionally, it finds application in agriculture as a soil amendment to improve …Web

Gypsum, from either nature or industrial by-products, can be a lower-cost and cleaner alternative binder to Portland cement used in construction projects, such as …Web

This study used Grade 42.5 ordinary Portland cement containing 80% clinker, 5% gypsum, and 15% mineral additives. Its specific surface area was 330 m 2 /kg, ... linear expansion tests of the cement paste were conducted according to JC 313-2009 "The Test Method for the Linear Expansion of Cement Paste". The expansion-rate test was …Web

a significant expansion of the application areas of products based on them. Gypsumcement-pozzolan binder is a composition of gypsum binder, Portland cement and active mineral additives. Depending on the type and composition of each component, as well as the method of preparation, the physicochemical and mechanical properties of theWeb