Papers by Keyword: Limestone Powder

Abstract: According to the recent community-based structures enlargement, specification, and diversification. It needs appropriate construction materials in terms of intensity and environmental aspects. Thus, in manufacturing the cement using micro limestone powder that is main material. It is also expected to save energies and reduces CO₂, by using the blast furnace slag and fly ash which are mitigated environmental load construction materials that emerged. In this research, the durability aspect tries to be grasped considering the chemical property according to the coherence of the hydration product. Consequently, the compressive strength was measured over 30Mpa on 3rd. In addition, according to the content of the limestone powder, the setting time is promoted. It has the feature expanded in the length change. And it is determined because the possibility of replacing the existing for construction material such as it is measured compared with the time to use the portland cement usually that flexural strength is high with the age 7 days ago, so it is sufficient.

Abstract: Using the fast freeze-thaw test method, we tested the loss modulus and compressive strength of steel slag-limestone powder concrete after 0,25 times,50 times,75 times,100 times freeze-thaw cycle,studied the mechanical properties and frost resistance performance after the freeze-thaw cycle. The results showed that adding a certain amount of steel slag-limestone powder does not affect the anti-frost property of concrete; established different dosage of steel slag concrete freeze-thaw damage model: y = a + bx + cx2, degree of fitting is better; large quantity of steel slag used in concrete shall be a wider range of research.

Abstract: In order to study the suppression effect of increasing concrete shrinkage induced by limestone powder, the aliphatic water reducer and polycarboxylate superplasticizer was used in experiments about effect of limestone powder content on concrete shrinkage. The results showed that the concrete shrinkage increased as the limestone powder content increasing. Comparing to the aliphatic water reducer, the polycarboxylate superplasticizer showed obviously effect on concrete shrinkage suppression. Besides, the polycarboxylate superplasticizer can reduce the sensitivity of concrete cracking. The polycarboxylate superplasticizer using in concrete can effectively reduce the emission amount and environmental pollution in the production process of artificial sand, simultaneously, this is helpful to improve the volume stability of concrete.

Abstract: This study investigates the influence of two fine mineral fillers on the main characteristics of tile adhesives – limestone powder and silica flour Silverbond 50. These fillers were added in various dosages: from 2.5% to 10% by weight of mixture.

Abstract: 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.

Abstract: The mining and processing of limestone in the state of Rio de Janeiro, southeast of Brazil, generates a considerable amount of small particles, like a powder ,which is commercialized as a by product. In principle, this inert limestone powder could be recycled as part of another civil construction material. Thus, the objective of this work was to characterize a limestone powder by its physical properties, chemical analysis and microstructural aspects. The results were compared with the characteristics of a common cement and a conventional sand to be possibly applied in the fabrication of limestone incorporated concrete blocks. It was found that the limestone powder has physical, chemical and microstructural characteristics satisfactory for concrete blocks incorporation.

Abstract: This paper study on the mortar strength, particle gradation and mortar fluidity of binary and ternary systems for cementitious materials with limestone powder or fly ash, analyze the influence of limestone powders with different specific surface areas and contents on the performance of cementitious materials; and research the performance of limestone powder in cementitious materials by means of micro analysis. The result shows that the limestone powder can not only work as the filling material, but also speed up the early hydration of cement in the cementitious material system.

Abstract: 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.

Abstract: In this study, a high-strength concrete containing 25% super-fine fly ash and 10% limestone powder was prepared, and its properties were investigated by comparing with those of pure cement concrete. The results show that the concrete containing super-fine fly ash and limestone powder can get a larger initial slump and a smaller slump loss than the pure cement concrete with the same super plasticizer content. In the case of almost the same 28 days' compressive strength, the concrete containing super-fine fly ash and limestone powder exhibits a lower adiabatic temperature rise, a lower early strength, a higher late strength, a lower permeability, and a larger carbonation depth than the pure cement concrete.

Abstract: The use of orthogonal test method, the concrete mixed with limestone power and fly ash was carried out static compressive experiment, and contrast with the experiment of single doped with limestone powder and fly ash concrete. The experimental result demonstrated that the compressive strength enhancement effect of the concrete mixed with limestone power and fly ash was obvious. The importance of each factor affecting static compressive strength as follows: water-cement ratio, the amount of fly ash, the amount of limestone powder, sand ratio. The concrete compressive strength reached the maximum when the water-cement ratio reached 0.3, the limestone powder content reached 15%, the fly ash content reached 10%, and sand ratio reached 34%.