Influence Of Limestone Powder Research Articles

Production of vaterite via wet carbonation of carbide residue: Enhancing cement properties and CO2 sequestration

The influence of limestone powder (primarily composed of calcite) on hydration and properties of concrete has been extensively researched. However, there is limited understanding of how different calcium carbonate (CC) polymorphs affect cement hydration due to the difficulty in formation of vaterite. Therefore, preparing calcite and vaterite from solid waste carbide residue (CS) by wet carbonation and examining influence of these two CC polymorphs (0–20 %) on cement hydration and properties are comprehensive investigated in the paper. The results reveal that pure cubic calcite can be obtained through CS carbonation, while high-purity spherical vaterite can be synthesized using glycine as a regulator. The specific surface area (SSA) of spherical vaterite (15.47 m2/g) is approximately three times that of calcite (4.8 m2/g) with a comparable particle size distribution (PSD). The addition of calcite reduces the flowability of cement, whereas vaterite enhances it. The cement mortar with calcite demonstrates a lower compressive strength, while the incorporation of vaterite results in a higher or comparable compressive strength in contrast to control sample. Compared with control cement hydration, new hydration products, like monocarbonate aluminate and hemicarbonate aluminate, are formed with the addition of both calcite and vaterite. The metastable vaterite exhibits increased reactivity. The research presents a novel approach for the valorisation of solid wastes through CO2 sequestration, offering insights into the preparation of highly added-value products.

Degradation of the bond performance between composite limestone powder concrete and steel bars under a sulfate freeze–thaw environment

An experimental investigation was conducted to explore the degradation of the bond performance between five types of composite limestone powder concretes and steel bars under a sulfate freeze–thaw environment. The failure model, ultimate bond strength, peak slip and bond–slip curve were researched. Three types of anchorage lengths were adopted in the investigation. The results indicated that limestone powder and fly ash reduced the ultimate bond strength and increased the peak slip of split failure. Slag increased the ultimate bond strength and reduced the peak slip. The bond performance between the composite limestone powder concrete and steel bars decreased with increasing anchorage length. Limestone powder exacerbated the degradation of the bonding performance of concrete under freeze–thaw cycles, while slag slowed the reduction in ultimate bond strength and corresponded with lower peak slip and more brittle failure. The constitutive relationship between the conventional environment τ (s, d/L) and the sulfate freeze–thaw environment τ (s, fts) was established, and the correction factor for the critical anchorage length of the sulfate freeze–thaw environment was derived. Thus, the influences of limestone powder, fly ash and slag on the critical anchorage lengths were analysed.

Deterioration of concrete containing limestone powder exposed to sulfate attack at ambient temperature

This study investigates the deterioration of concrete containing limestone powder exposed to sulfate solution under ambient temperature (20~25 °C). Microstructure and mineral phases within the attacked concrete were measured by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). It was found that the addition of limestone powder increased the initial porosity of concrete. Consequently, a larger amount of SO2–4 ions diffused into the concrete containing limestone powder, and their degree of deterioration caused by sulfate attack increased with the increase in limestone powder content. At ambient temperature, gypsum and ettringite were the major attack products, respectively within the surface and nearsurface portions of concrete containing limestone powder, which was consistent with the products of sulfate attack within concrete without limestone powder. Therefore, the type and distribution of the attack products in concrete had not been revised due to the addition of limestone powder. Nevertheless, the adverse influence of limestone powder on the sulfate resistance of concrete, even at ambient temperature, should be considered. Furthermore, effective measures should be implemented to improve the durability of concrete containing limestone powder in this environment.

Influence of Limestone Powder and Fly Ash on the Freezing and Thawing Resistance of Roller-Compacted Concrete

Roller-compacted concrete (RCC) comprises the same raw materials used in conventional concrete, but with different proportions. It is dry and has a low paste volume. Large volumes of fly ash are commonly used in the construction of roller-compacted concrete dams (RCCD) and pavements (RCCP). However, it is not as abundant as limestone powder. The latter is also cheaper and environment-friendly. This study aims to investigate the optimal amount of limestone powder that can be used in RCC to reduce both cement and fly ash. The effects of limestone powder and fly ash on the water absorption, compressive strength, and freeze-thaw resistance of RCC were evaluated. Eight different combinations of the mineral admixtures were tested, with limestone powder and fly ash contents up to 35% and 30%, respectively. A decline in density was observed when the cement replacement level was greater than 30%. This also led to an increase in porosity and permeability. Two mix designs denoted as LS30 and LS30FA10, demonstrated satisfactory results after 100 freeze-thaw cycles with relative dynamic modulus of elasticity (RDME) values of 73% and 70%, respectively. Their corresponding mass loss was 3.05% and 3.72%, which were below the code specified limit (5%).

Influences of limestone powder on the resistance of concretes to the chloride ion penetration and sulfate attack

Influences of limestone powder on the resistance of concretes to the chloride ion penetration and sulfate attack with a constant water/binder ratio and a constant 28-day compressive strength were studied. The sensitivity of the properties of concrete to the initial moist curing time was also explored. The results indicate that, under a constant water/binder ratio condition, the resistance to sulfate attack of concrete deteriorates with the increasing of limestone powder content, and the resistance to chloride ion penetration decreases when the replacement ratio of limestone powder is 24%. As the initial moist curing time declines, the reducing magnitude of the properties of concrete containing limestone powder is larger than that of plain cement concrete. Nevertheless, lowering the water/binder ratio of concrete containing limestone powder can significantly reduce the sensitivity of the properties of the concrete to the initial moist curing time. No matter how long the initial moist curing time is, replacing cement with 8% limestone powder can improve the resistance of concrete to sulfate attack. Concrete with up to 24% limestone powder addition can still obtain a resistance to chloride ion penetration and sulfate attack similar to plain cement concrete on the premise of a constant 28-day compressive strength. Moreover, it was found that both the crystallization of sodium sulfate and the formation of ettringite collectively result in the deterioration of concrete subjected to the sulfate solution.

Influence of recycled fines on the flexural creep of self-compacting concrete beams under four-point bending load

The current need to find new technical solutions respecting sustainable development leads to study the aging character of concrete, especially of self-compacting concrete (SCC). The objective of this work is to experimentally assess the flexural creep of SCC beams (section 10 × 10 × 120 cm3) under a constant four-point bending stress, by studying the influence of limestone powder (LP) total replacement by recycled fines namely marble powder (MP) glass powder (GP) and granulated blast furnace slag (GBFS) on endogenous and total creep. So, four sets of beams, with the same basic formulation (W/P ratio, paste volume), have been put under a constant stress of 1.3 MPa to determine the total and endogenous creep. Besides, the compressive strength, the four-point bending strength and the elastic modulus were measured. The results indicate that LP total replacement by GP or GBFS reduces the total creep and creep coefficient, while its total replacement by MP increases this coefficient.

Influence of limestone powder on mechanical, physical and self-healing behavior of Engineered Cementitious Composites

Environmental considerations have led to a global trend of using blended cements instead of ordinary Portland cement; cements containing limestone powder (LP) have recently entered the market. This research focuses on the effect of replacing LP content with cementitious material on the performance of Engineered Cementitious Composite (ECC) containing high-volume fly ash (FA). For this purpose, ECC mixtures were created in which cement and FA were partially replaced by 5%, 10% and 20% of LP and ECC mixture without LP (as control). The samples were precracked at the age of 28days and left under continuous water curing (CW) for recovery of their properties. Compressive strength, modulus of rupture (MOR), mid-span beam deformation capacity, rapid chloride penetration testing (RCPT) and resistivity testing were used to assess the mechanical, physical and self-healing capability of ECC mixtures. Experimental results show that all mixtures exhibited self-healing with slight differences. Microstructure was also assessed using SEM–EDS and XRD analysis. The microstructural analysis of healed cracks in LP-incorporated ECC mixtures showed the presence of calcite, portlandite and C–S–H gels as well as monocarboaluminate, which confirmed a possible reaction between FA and LP. Due to self-healing, the recovery in mechanical and durability performance of the mixtures proposed in this research is anticipated to positively affect life cycle costs and lead to increased civil infrastructure sustainability.

Partially Replacing Fly Ash with Limestone Powder in the Paste - Influence and Characterization

Paste filling is an important research direction of coalmine “green mining” which can dispose coalmines solid waste and achieve environmental protection. The mechanical properties such as compressive strength, workability, ultimate tension value, shear strength and splitting strength of paste, in which the fly ash was partially replaced by limestone powder, was studied. Adiabatic temperature rise, setting time, shear strength, permeability, frost resistance and dry shrinkage of different substitution rate were investigated and the results were compared with traditional paste. The test results showed that the influence of limestone powder on workability, permeability and frost resistance performance of paste was slight, the setting time of paste were shortened, adiabatic temperature rise and mechanics performance of paste were decreased, dry shrinkage value was increased with limestone powder content increasing.

Performance Analysis of Fine Mineral Fillers in Gypsum Plasters

This study investigates the influence of limestone powder and silica flour used as fine mineral fillers on the main characteristics of gypsum plaster. Fine mineral fillers were added in various dosages from 2.5% to 20.0%.

Influence of Limestone Powder on the Hydration of Cement-Steel Slag Composite Binder

Steel slag and limestone powder are both mineral admixtures for cement or concrete. Steel slag can react with water and produce hydration products. The hydration activity of limestone powder is very limited. This paper investigated the influence of limestone powder on the hydration of cement-steel slag composite binder by determining the hydration heat and compressive strength. The results show that limestone powder can promote the early hydration of the composite binder and the compressive strength of mortar increases by replacing part of steel slag by limestone powder. However, at the age of 28 days, the positive effect of limestone powder is almost equal to its negative effect, so the compressive strength of mortar changes little by replacing part of steel slag by limestone powder.

Influence of limestone powder on hydration properties of complex binders

In this paper, the influence of limestone powder on hydration properties of complex binder was studied by determining compressive strength of mortars and hydration heat of complex binders. Meanwhile, microcosmic analysis such as mercury intrusion porosimetry, scanning electron microscope and X-ray diffractometer, were also performed on those mortars. Because of the smaller particle size of limestone powder, it can form better gradation as fillers in the cementitious system. With the increasing limestone powder content, the proportion of small pores with diameter smaller than 50 or even 20 nm, which has little effect on the properties of the composite, increased and could make pores finer and improve the pore structure. At earlier period (28 days) limestone powder acts filling and accelerating effects by speeding up the hydration process of complex binder, but it will react with ordinary Portland cement to produce calcium monocarboaluminate hydrates, acting its activate effect at later period (180 days). Owing to its activate effect, it will improve early compressive strength, and also increase hydration exothermic rate while shorten its induction period.

Limestone Powder- A New Type of Mineral Admixture for Dam Concrete

Influences of limestone powder on the hydration progress of cement and the properties of dam concrete were studied in this paper. The results show that, as mineral admixture, limestone powder accelerates the cement early hydration and takes part in this hydration which produces the calcium monocarboaluminate hydrate, but, limestone powder doesnt have the pozzolanic activity. Limestone powder has an adverse impact on the pore system of hardened pastes, especially these pores size range from 3 nm to 107 nm. Fortunately, the pore system will be optimized by using some fly ash instead of part of limestone powder. Limestone powder, no matter used alone or blended with fly ash or ground blast furnace slag to form a double-doped material, can be used as mineral admixture for the dam concrete including conventional and roller-compacted concrete. Compared with fly ash, it increases concrete water content and improves the 7 days strength, but almost has no function on the 90 days strength.

Influences of Limestone Powder on the Performance of Self-Compacting Concrete

This paper primary researched the influence of limestone powder on the workability, the strength performance and the volume stability of self-compacting concrete (SCC). Results showed that the workability of self-compacting concrete was improved greatly by mixing proper limestone powder; besides, limestone powder could improve early age strength of concrete obviously, but had little influence on long age strength; the self-shrinkage of concrete increased as the admixture of limestone powder increased. The content of limestone should be capped at 10% and the optimum mix amount is about 7%.

The Frost Resistance of High Strength Concrete Containing Super-Fine Mineral Admixture

The influence of limestone powder, lithium slag and air-entraining agent on frost resistance of concretes was investigated by freezing-thawing cycle tests. The elastic moduli and weight loss rates of concretes before and after tests were checked. The results show the introduction of limestone powder into concrete is disadvantageous to its frost resistance, which gets worse as limestone powder contents increase. Air-entraining agent used in concrete can improve its frost resistance. The frost resistance grades of concrete containing a certain of air-entraining agent (0.2-0.4‰) can reach F1500, while it is below F300 for limestone powder concrete which is absent of air-entraining agent. The addition of lithium slag into concrete is helpful to frost resistance, and optimum mixing amount is 10%.

Chlorine Ion Penetration Resistance of Concretes Containing Super-Fine Limestone Powder

The influence of limestone powder, air-entraining agent and water binder ratio on chlorine ion (Cl-) penetration resistance of concretes was investigated by rapid Cl- penetration tests. The results show that the fineness of limestone powder is a key factor to Cl- penetration resistance of concrete. It can improve Cl- penetration resistance by introducing super fine limestone powder into concrete. Cl- penetration resistance of concrete increases as curing time increases. The concrete with lower water binder ratio has better Cl- penetration resistance. The introduction of air-entraining agent into concrete can enhance Cl- penetration resistance by improving micro pores structure. The optimum mixing amount is 0.3‰.

Research on the Application of Limestone Powder in Concrete Engineering

This thesis first analyzes the necessity for the application of limestone powder produced in Lime Ridge from Xixia County, Henan Province. It also tests the concrete performance with different composition materials and does research on the influence of limestone powder on concrete strength by adding limestone powder instead of fly ash in fly ash concrete. It then finds out the reasonable volume of limestone powder to meet the concrete’s performance, in order to guarantee the scientific and effective use of limestone powder in concrete engineering.

Influence of Limestone Powder on Performance of the Pre-Mixed Cement Mortar

Effect of the different contents of limestone power (LSP) in manufactured-sand (MS) is investigated in respect of the workability, setting time and compressive strength. The results show that the contents in a certain range can significantly increase the consistency, Specific density of the fresh mortar, and improve comprehensive strength of the hardened mortar due to LSP deduced the porosity and improved the pore structure.

Influence of Limestone Powder on Immobilization of Chlorine Ion of Portland Cement

The effect of limestone powder on immobilization of chlorine ion of Portland cement was studied by the method of the chemical analysis. The immobilization of chlorine ion of Portland cement, which was hardened by cement clinker or cement clinker and gypsum mixed limestone powder with different proportions, was tested at 28d. The results show that the amount of immobilization of chlorine ion of Portland cement increases more than doubled, and the free chlorine ion content decreases 41% without gypsum, when the limestone powder content increases from 0% to 12%; the immobilization content of chlorine ion increases first, and then decreases, the free chlorine ion content decreases a little with gypsum, when the limestone powder content increases from 0% to 8% .

The Influence of Limestone Powder on Fluidity, Strength and Hydration of Cement Mortar

An experimental program has been conducted to investigate the influence of limestone powder (LP) on fluidity, strength, and hydration of cement mortar. Four laboratory grinds were prepared using a ball mill. The relationship between roundness of the LP and water requirement of paste, fluidity and strength of mortar was studied. The influence of LP on hydration of cement was investigated. Hydration products were determined by X-ray diffraction (XRD) analysis. Test results show that the roundness of LP significantly affected the water requirement of paste, fluidity and strength of mortar. In addition, the sites for the nucleation and growth of hydration products, provided by LP, accelerate the hydration of cement at early ages. While the enhancement of cement hydration at later ages mainly due to the formation of calcium aluminate monocarbonate.

Influence of Limestone Powder as Partial Replacement of Cement on Concrete and the Effect of High Temperature on It

Influence of Limestone Powder as Partial Replacement of Cement on Concrete and the Effect of High Temperature on It