Evaluate the compressive strength of cement paste modified with high reactivity attapulgite and affected by curing temperature

Zghair, Luma Abdul Ghani; Hamad, Hind Hussein; Mohamad, Safaa A.; Al‐Hamd, Rwayda Kh. S.

doi:10.1016/j.matpr.2021.09.058

Cited by 18 publications

(4 citation statements)

References 12 publications

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“…Attapulgite [AlH9MgO15Si4] is a variety of clay characterized by its fibrous, rod-shaped structure with palygorskite as its main mineral component [70], [72]. It is characterized by an open-channel structure that gives rise to elongated, needle-shaped crystals [71]. Attapulgite is an effective supplementary cementitious material [69], [70], [71].…”

Section: X-ray Diffraction Analysis Of Fly Ash and Ggbsmentioning

confidence: 99%

“…It is characterized by an open-channel structure that gives rise to elongated, needle-shaped crystals [71]. Attapulgite is an effective supplementary cementitious material [69], [70], [71]. The introduction of a small quantity of attapulgite substantially impacted the formation of the cement paste's structural network, leading to a more flocculated internal arrangement.…”

Section: X-ray Diffraction Analysis Of Fly Ash and Ggbsmentioning

confidence: 99%

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Mitigation Measures of Swelling Characteristics in Alkali-Contaminated Red Earth using Fly Ash and GGBS Blends

Kumar Darapu,

Vindula

2023

IOP Conf. Ser.: Earth Environ. Sci.

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Alkali contamination induces swelling in the inherently non-swelling soils, resulting in heave severely damaging the sub and superstructures. Stabilization measures must be taken in vulnerable areas to prevent such colossal losses. Considerable research has been conducted regarding the swelling behavior of soils contaminated with alkalis and the impact of subsequent stabilization techniques utilizing different industrial byproducts and pozzolanic materials. However, there is a paucity of such studies on the Red Earth (RE) of the Visakhapatnam region. Furthermore, limited attention was given to the effects of extremely low concentrations of alkalis on the swelling behavior of soils. RE in the study area of the Visakhapatnam region predominantly consists of quartz, kaolinite, and hematite. In phase 1 of the experimental analysis, RE was contaminated with a highly dilute NaOH solution (0.05 N), and the resulting swell characteristics were investigated. A free swell of 10% was observed. One-dimensional standard oedometer tests revealed an equilibrium swelling of 5.6%, indicating significant potential for substantial heave and subsequent damage. X-ray diffraction (XRD) analysis revealed the formation of natrolite and analcime zeolites with a hollow structure, which caused the swell. Peaks of silicate minerals like paragonite and ussingite were also observed, indicating the dissolution of authigenic minerals and new precipitations even at lower concentrations of NaOH. In phase 2, swell tests were conducted on a mixture of contaminated red earth (50% w/w), fly ash (25% w/w), and ground granulated blast furnace slag (GGBS, 25% w/w), and it was observed that the swelling was completely arrested. XRD analysis unveiled that even though siliceous zeolites were formed, the development of chrysotile, attapulgite, tobermorite, and dicalcium silicate effectively inhibited the swelling with their pozzolanic behavior.

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Section: X-ray Diffraction Analysis Of Fly Ash and Ggbsmentioning

confidence: 99%

Section: X-ray Diffraction Analysis Of Fly Ash and Ggbsmentioning

confidence: 99%

Mitigation Measures of Swelling Characteristics in Alkali-Contaminated Red Earth using Fly Ash and GGBS Blends

Kumar Darapu,

Vindula

2023

IOP Conf. Ser.: Earth Environ. Sci.

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“…Der (2018) used SAFIR software to simulate heavily reinforced concrete columns exposed to fire and the results of temperature distribution, axial deformation, and failure agreed well with the experimental results. Studies on the effect of fire have also been carried out on other types of columns, for example, concrete filled steel tube columns (CFST) (Cao and Trinh, 2023; Han, 1998), reinforced CFST columns (Xu and Liu, 2013), recycled aggregate CFST columns (Yang et al, 2016), and materials, for example, mortar made of volcanic ash (Mohamad et al, 2020), high-reactivity attapulgite cement paste (Zghair et al, 2022), etc.…”

Section: Introductionmentioning

confidence: 99%

Residual axial strength of reinforced concrete columns after exposure to standard and non-standard fires

Cao,

Ngo

2024

Advances in Structural Engineering

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This study investigated the residual axial strength of reinforced concrete (RC) columns after exposure to standard and non-standard fires. Experiments and theoretical analyses were performed on 30 RC columns, which were divided into five groups: one group (the control group) was not exposed to fire; two groups were exposed to 30-min and 45-min ISO 834 standard fires; and the other two groups were exposed to 60-min and 75-min non-standard fires. These postfire specimens were axially loaded until they failed. The experimental results showed that 30-min and 45-min ISO 834 fires decreased the residual strength by 11.6% and 17.4%, respectively. 60-min and 75-min non-ISO 834 fires caused similar reductions in the residual axial strength of postfire RC columns, although the durations of these non-standard fires were considerably longer. This experimental result confirmed that the maximum temperature, rather than the fire durations, of non-standard fires governed the reduction in the residual axial strength. In theoretical analysis, the axial strength of postfire RC columns can be calculated using the proposed model, which combines the confinement model, the 500°C isotherm method, and the distribution model of temperature. The proposed model can appropriately predict the residual axial strength of postfire columns when the fire closely follows the ISO 834 fire. The inaccuracy of the model significantly increases when the fires are non-ISO 834 fires. Two concepts, namely equivalent area and maximum temperature, were introduced to address the issue. The concept of maximum temperature successfully addressed the above-mentioned issue and exhibited superiority over the concept of equivalent area. This result reaffirmed the superior governing characteristic of the maximum temperature compared with the duration of non-standard fires, as evidenced in the experimental results. The proposed models would be useful for engineers in practice when evaluating the residual axial strength of both standard and non-standard postfire RC columns.

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“…High reactive attapulgite is obtained by thermally activating attapulgite clay with a high alumino-silicate content. This process allows for the production of attapulgite with desired characteristics, such as high reactivity and/or proper fineness, as it is not a waste material or by-product and can be produced in a controlled manner [23][24][25].…”

Section: Introductionmentioning

confidence: 99%

Cold-Bonded Lightweight Synthetic Aggregate Involving High Reactive Attapulgite at Different Curing Conditions

Abbas

2023

ETJ

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SLA was fabricated using HRA and PC via a cold-bonded process • Different percentage levels of HRA and PC were used • SLA with a density of 793 kg/m 3 can be producedThis study aimed to develop an eco-friendly, lightweight, and synthetic aggregate (SLA) based on clay suitable for use in structural lightweight concrete. The researchers utilized the cold-bonded pelletization process to agglomerate pozzolanic materials, specifically attapulgite extracted from a quarry, and crushed into a fine filler. The appropriate calcination temperature for manufacturing this clay as a pozzolanic material is 750℃. A total of 22 mixes were created using a combination of high reactive attapulgite (HRA) and cement (PC), with the attapulgite replacement rate varying from 100-50% by a 10% decrement. Different types of curing methods, including oven-dry, oven-water, room-water, and room-room, were applied. The aggregate properties were evaluated to determine density, specific gravity, water absorption, aggregate impact value, crushing strength, and compressive strength. The results revealed that it could produce lightweight synthetic aggregate from clay-based materials with a bulk density of 793 kg/m 3 with suitable physical and mechanical properties. As the percentage of cement in the mixture increased, the specific gravity and density were increased to 18.12% and 36.61%, whereas impact and crushing values of aggregate improved by 81.83%. This, in turn, leads to a significant boost in compressive strength up to 100.94%. Furthermore, there is a noticeable decrease in absorption. Moreover, the aggregate held under oven water positively impacts the strength development of cement-based composites.

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Evaluate the compressive strength of cement paste modified with high reactivity attapulgite and affected by curing temperature

Cited by 18 publications

References 12 publications

Mitigation Measures of Swelling Characteristics in Alkali-Contaminated Red Earth using Fly Ash and GGBS Blends

Mitigation Measures of Swelling Characteristics in Alkali-Contaminated Red Earth using Fly Ash and GGBS Blends

Residual axial strength of reinforced concrete columns after exposure to standard and non-standard fires

Cold-Bonded Lightweight Synthetic Aggregate Involving High Reactive Attapulgite at Different Curing Conditions

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