Replacement Ratio Of Slag Research Articles

Predicting the compressive strength of ground granulated blast furnace slag concrete using artificial neural network

In this study, an artificial neural networks study was carried out to predict the compressive strength of ground granulated blast furnace slag concrete. A data set of a laboratory work, in which a total of 45 concretes were produced, was utilized in the ANNs study. The concrete mixture parameters were three different water–cement ratios (0.3, 0.4, and 0.5), three different cement dosages (350, 400, and 450 kg/m 3) and four partial slag replacement ratios (20%, 40%, 60%, and 80%). Compressive strengths of moist cured specimens (22 ± 2 °C) were measured at 3, 7, 28, 90, and 360 days. ANN model is constructed, trained and tested using these data. The data used in the ANN model are arranged in a format of six input parameters that cover the cement, ground granulated blast furnace slag, water, hyperplasticizer, aggregate and age of samples and, an output parameter which is compressive strength of concrete. The results showed that ANN can be an alternative approach for the predicting the compressive strength of ground granulated blast furnace slag concrete using concrete ingredients as input parameters.

고로슬래그 분말도가 시멘트 페이스트의 유동특성에 미치는 영향

In this study, the rheological properties of cement pastes containing blastfurnace slag of different fineness were investigated. The fluidity of cement pastes with low Blaine value blastfurnace slag was increased with decreasing the plastic viscosity and the yield stress of pastes. And the optimum dosage of polycarboxylate type superplasticizer to the cement pastes was confirmed according to the fineness and the replacement ratio of blastfurnace slag. All cement pastes showed the thixotropy behavior. And also it was formed that the segregation range of cement pastes was occurred below 10 D/㎠ of the yield stress and below 350 cPs of the plastic viscosity by the coaxial cylinder viscometer.

Optimal Mixture Proportion for High Performance Concrete Incorporating Ground Granulated Blast furnace Slag

In this study, a mix design for self compacting concrete was based on Okamura's method and concrete incorporated just a ground granulated blast furnace slag. Replacement ratio of slag is in the range of <TEX>$20-80\%$</TEX> of cement matrix by volume. For the optimal self compactability in mixture incorporating ground granulated blast furnace slag, the paste and mortar tests were first completed. Then the slump flow, elapsed time of 500mm slump flow, V funnel time and filling height by U type box were conducted in concrete. The volume of coarse aggregate in self compacting concrete was in the range of <TEX>$50-60\%$</TEX> to the solid volume percentage of coarse aggregate. Finally, the compressive and splitting tensile strengths were determined in the hardened self compacting concrete incorporating ground granulated blast furnace slag. From the test results, it is desirable for self compacting concrete that the replacement of ground granulated blast furnace slag is in the range of <TEX>$40-60\%$</TEX> of cement matrix by volume and the volume of coarse aggregate to the solid volume percentage of coarse aggregate with a limit of <TEX>$55\%$</TEX>.

고로슬래그미분말의 분말도 및 대체율에 따른 콘크리트의 공학적 특성 및 내구특성에 관한 실험적 연구

As a part of efforts for conformity of demand to high quality of concrete and for solution of economic problem, blast-furnace slag has been utilized by means of cement replacement. With utilization of blast-furnace slag, superior performance can be ensured, environmental pollution can be prevented and economical advantage can be obtained. But blast-furnace slag has a lot of disadvantages like retardation of strength manifestation etc. in field construction, so properties examination of concrete using blast-furnace slag instead of cement is necessary. For upper necessity, it is planed that basic data for utilization and performance management of blast-furnace slag by means of cement replacement is presented with experimental comparison and investigation of engineering properties of concrete according to the replacement ratio and fineness of blast-furnace slag.

Recovering Industrial Sludge-Derived Slag as Fine Aggregate

This study presents the result of using melting to recover both industrial sludge slag (the main constituent of which is calcium fluoride) and water works sludge slag as fine aggregate in cement. The main characteristics of both slag and cement mortars were measured to evaluate the feasibility of using slag as aggregate. In this study, the slag replacement ratios were 0, 10, 20, 30, 40, and 50% (w/w), and the curing periods were 7, 28, and 90 days. Slag quality was determined according to the standards of fine aggregates in the ASTM specifications, and cement mortars with various slag replacement ratios were evaluated based on their compressive strength, and Toxicity Characteristic Leaching Procedure (TCLP). The crushed slag produced in this study met the ASTM standards for fine aggregate, including gravity, unit weight, absorption, and grading, and the TCLP leached concentrations are far below existing limits, establishing the safety and suitability of slag as fine aggregate. The TCLP leached concentrations of slag and cement mortar were not significantly related to the replacement ratio, and declined with increasing curing period, revealing that the hydration strongly influenced metal leaching. The compressive strength test results of the cement mortars demonstrated that the optimal replacement ratio for maximizing compressive strength was 40%. This study also discussed the effects of replacement ratio and curing periods on cement mortars.

광물혼화재가 혼합된 다성분 페이스트 시스템의 레올로지 특성 평가

The rheological properties of cement paste system mixed with mineral admixtures (MAs) used to increase the strength and improve durability and fluidity of concrete were investigated. And cement paste systems were designed as one-, two- and three-ingredients blended paste systems. The rheological properties of paste systems were assessed by Rotovisco RT 20 rheometer (Hakke inc.) having a cylindrical serrated spindle. The rheological properties of one-ingredient paste systems were improved with increasing the dosage of superplasticizer. For two-ingredients paste systems, as increasing the replacement ratio of blast furnace slag (BFS) and fly ash (FA), the yield stress and plastic viscosity were decreased compared with non-replacement. In the ordinary portland cement (OPC)-silica fume (SF) paste systems, in accordance with an increase in the replacement ratio of SF, the yield stress and plastic viscosity were increased steeply. For three-ingredients paste systems, both OPC-BFS-SF and OPC-FA-SF paste systems, the rheological properties were improved compared with the only replacement of SF. In the case of both two-and three-ingredients paste systems, the rheological properties using BFS were improved more than FA.

都市ごみガス化溶融スラグのコンクリート用細骨材としての利用

In recent years, a technique for producing slag (MSW slag) by melting municipal solid waste or its incinerated ash at more than 1,300°C, and cooling it has been developed. This study examines 4 kinds of gasification MSW slag (rotary kiln, thermo select, fluidized-bed and coke-bed) and discusses the possibility of its utilization as fine aggregate for concrete. It is clear that the possibility is high because almost every MSW slag satisfies the quality standard as fine aggregate for concrete. Moreover, a concrete product of 50% slag replacement ratio to fine aggregate had no problem with strength and freeze-thaw resistance. It is, therefore, judged that the product can be put to use.

建設材料特集 高ビーライトセメントおよび高ビーライト系混合セメントを用いたコンクリートの諸特性

Recently in Japan, the demand for low heat cement to prevent thermal cracks is growing higher because of scaling up of concrete structures. Usually, moderate heat portland cement and binary or ternary blended cement in which ground blast-furnace slag and fly ash were admixed have been used as low heat cement. However, such blended cements have several problems. For examples, the heat of hydration of moderate heat cement is not sufficiently low. The quality of blended cement is not stable and it is very difficult to control and stabilize its quality because of incorporating industrial by-products, and the rate of carbonation is quite fast. Therefore, belite-rich cement is expected much as low heat cement which is more durable and effective to prevent thermal cracks.In this study, the effect of the content of belite in cement on the property of concrete was investigated by using four kinds of belite cements in order to make the characteristics of belite-rich cement clear. The relations between the replacement ratio of blast-furnace slag and adiabatic temperature rise or strength were also investigated using belite-rich cement containing about 60% of C2S, under the condition that the replacement ratio of fly ash was kept 30% constant.