scholarly journals Prediction on Compressive and Split Tensile Strengths of GGBFS/FA Based GPC

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4198
Author(s):  
Songhee Lee ◽  
Sangmin Shin
Keyword(s):  
Curing Temperature ◽  
Test Results ◽  
Portland Cement Concrete ◽  
Contributing Factors ◽  
Split Tensile Strength ◽  
Equivalent Age ◽  
Granulated Blast Furnace Slag ◽  
Model Predictions ◽  
Taguchi Orthogonal Arrays ◽  
Cylindrical Test

Based on rate constant concept, empirical models were presented for the predictions of age-dependent development of compressive and split tensile strengths of geopolymer concrete composite (GPCC) with fly ash (FA) blended with ground granulated blast furnace slag (GGBFS). The models were empirically developed based on a total of 180 cylindrical test results of GPCC. Six different independent factors comprising of curing temperature, the weight ratios of GGBFS/binder, the aggregate/binder, the alkali solution/binder, the Na2SiO3/NaOH, and the NaOH concentration were considered as the variables. The ANOVA analyses performed on Taguchi orthogonal arrays with six factors in three levels showed that the curing temperature and ratio of GGBFS to binder were the main contributing factors to the development of compressive strength. The models, functionalized with these contributing factors and equivalent age, reflect the level of activation energy of GPCC similar to that of ordinary Portland cement concrete (OPC) and a higher frequency of molecular collisions during the curing period at elevated temperature. The model predictions for compressive and split tensile strength showed good agreements with tested results.

Evaluation of Contributing Factors on Strength Development of Lime Stabilized Artificial Organic Soils Using Statistical Design of Experiment Approach

2014 ◽  
Vol 905 ◽  
pp. 362-368 ◽  
Author(s):  
Felix N.L. Ling ◽  
Khairul Anuar Kassim ◽  
Ahmad Tarmizi Abdul Karim ◽  
S.C. Ho
Keyword(s):  
Organic Matter ◽  
Statistical Design ◽  
Organic Soil ◽  
Curing Temperature ◽  
Organic Soils ◽  
Strength Development ◽  
Test Results ◽  
Contributing Factors ◽  
Strength Enhancement ◽  
Factor Interactions

Lime is widely used as chemical stabilizer in soft soil stabilization. However, lime is reported to be less effective when dealing with organic soil. It is believed that the organic matter in the soil will retard the pozzolanic reaction which is responsible for strength enhancement. The heterogeneity nature of the organic matter in the soil makes the study complicated and reduced the repeatability of the test results. Hence, artificial organic soil with known organic matter and content are preferred by researchers when repeatability of the test results are required in determining the influential effect of each contribution factor. Various factors such as additive contents, effect of aging (curing periods), curing temperature, density of materials and moisture content are reported by previous researchers as the potential contributing factors towards the strength development. It is believed that the interaction of the factors also will contribute to the strength enhancement. Hence, this study is carried out to evaluate the contributing factors and its interactions on strength development of artificial organic soils with known type and contents of organic matter. Statistical design of experiment (DOE) approach was utilized to evaluate the factors and its interaction on the strength development of lime stabilized artificial organic soils by using commercial statistics package. Three main factors were investigated: effect of organic content, effect of curing periods, and effect of additive, while other factors namely curing temperature, molding water content, types of compaction and compactive effort were keep constant through controlled experiments. Processed kaolin (inorganic material) is mixed with humic acid (organic matter) to simulate the organic soil which comprised of inorganic soil and organic matter. The density of the soil specimen and its moisture content were recorded before and after the curing process. General Linear Model (GLM) was utilized to determine the significance of the main factors, two-factor interactions, and three factor interactions. The significance factors and interactions were utilized in multiple regression analysis to develop the strength prediction model which can be utilized to predict the strength of stabilized materials within the inference space defined by the experiment.

scholarly journals Strength and Durability Characteristics of Steel Fibre Reinforced Concrete with Mineral Admixtures

2019 ◽  
Vol 9 (1) ◽  
pp. 3893-3897
Keyword(s):  
Reinforced Concrete ◽  
Fly Ash ◽  
Steel Fibre ◽  
Mineral Admixtures ◽  
Fibre Reinforced Concrete ◽  
Test Results ◽  
Split Tensile Strength ◽  
Steel Fibre Reinforced Concrete ◽  
Granulated Blast Furnace Slag ◽  
Strength And Durability

The present investigation is carried out to study the strength and durability characteristics of steel fibre reinforced concrete, by replacing Ordinary Portland cement with Fly Ash, Ground Granulated Blast Furnace Slag (GGBS) and Metakaolin. In this study, cement is replaced by 30% and 40% with Fly Ash, GGBS and Metakaolin for M30 and M35 grades of concrete. Steel fibres @ 1% by weight of binder is used in all the mixes. Strength characteristics like compressive strength and split tensile strength are tested at 7 days and 28 days age. Additionally, durability tests such as water absorption and Sorptivity tests are conducted after 28days curing. The test results have shown that 30% replacement is optimum for strength criteria. And when metakaolin is used with fly ash, durability properties were improved and workability reduced.

scholarly journals Activation Energy for the Concrete Maturity Model – Part 2: New Model for Temperature Dependent Ea

2020 ◽  
Vol 62 (1) ◽  
pp. 107-124
Author(s):  
Claus Vestergaard Nielsen
Keyword(s):  
Activation Energy ◽  
Curing Temperature ◽  
Alternative Formulation ◽  
Early Age ◽  
Maturity Model ◽  
Test Results ◽  
Temperature Dependent ◽  
Arrhenius Model ◽  
Equivalent Age ◽  
Concrete Maturity

AbstractThe article addresses the modelling of the maturity of concrete. The apparent activation energy is the backbone of the Arrhenius model, which is typically used to model the maturity of concrete. The maturity (or the equivalent age) is influenced by the curing temperature and it is applied when modelling the hydration process and the hardening of concrete for instance in order to forecast the early-age strength to determine the time for removal of formwork or the time for prestressing. Part 1 of the article describes the background for the maturity model and the tests carried out as part of a large test programme at the DTI concrete lab. The tests were applying iso-thermal curing temperatures from 5°C to 60°C for various durations before measuring the compressive strength.Part 2 of the article presents a model for the activation energy based on these test results. An alternative formulation of the maturity model is suggested and compared with other similar concrete tests found in the literature for early-age strengths. The alternative model is shown to give better accuracy when modelling the early-age strengths of concrete. The tests include five different concretes, using three different cement types and the addition of fly ash.

scholarly journals A Statistical Study to Investigate the Efficiency of Steel and Polypropylene Fiber in Enhancing the Durability Properties of Concrete Composites

2018 ◽  
Vol 4 (6) ◽  
pp. 1254 ◽  
Author(s):  
Niraj Kumar Singh ◽  
Baboo Rai
Keyword(s):  
Volume Fraction ◽  
Polypropylene Fiber ◽  
Test Results ◽  
Portland Cement Concrete ◽  
Fiber Volume ◽  
Split Tensile Strength ◽  
Concrete Deterioration ◽  
Durability Properties ◽  
Positive Correlations ◽  
Concrete Matrix

Concrete deterioration is associated with factors like surface abrasion and transport of water through capillary action in the concrete matrix. These factors may catalyze other forms of deformation such as cracking and corrosion of reinforcing steel. This paper presents an experimental evaluation to compare the effectiveness of steel and polypropylene fiber in enhancing the mechanical and durability properties, in terms of impact, sorptivity, and abrasion. In the present study, abrasion resistance is strongly related to flexural strength as high correlation coefficient existed as compared to that of compressive strength and split tensile strength. Sorptivity test results demonstrated a substantial decrease in capillary porosity when PPF is used in concrete.  The average initial sorptivity versus fiber volume fraction represents a linear relationship with high R2 value. Positive correlations were also detected between abrasion and initial sorptivity of ordinary Portland cement concrete composite with polypropylene fiber. 

scholarly journals Salt-Frost Scaling of Concrete with Slag and Fly Ash - Influence of Carbonation and Prolonged Conditioning on Test Results

2020 ◽  
Vol 63 (2) ◽  
pp. 89-108
Author(s):  
Elisabeth Helsing ◽  
Peter Utgenannt
Keyword(s):  
Fly Ash ◽  
Frost Resistance ◽  
Test Results ◽  
Portland Cement Concrete ◽  
Supplementary Cementitious Material ◽  
Granulated Blast Furnace Slag ◽  
Binder Ratio ◽  
Swedish Experience ◽  
Entrained Air ◽  
Water To Binder Ratio

AbstractAccording to Swedish experience the slab method in CEN/TS 12390-9 is successful in predicting the salt-frost resistance of Portland cement concrete. However, doubts have been raised whether the same can be said when used on concrete with supplementary cementitious material, e.g. fly ash or ground granulated blast furnace slag (GGBS). Test results from concrete mixes with up to 35 % fly ash 65 % GGBS, with two different Portland cements and a water-to-binder ratio of 0.45 are presented in this paper. The tests were carried out with the standard method and with five modifications concerning the pre-conditioning of the specimens before freeze-thaw cycling. The age of the specimens at sawing was increased, the time in 65 % RH was prolonged and exposure to 1 % CO2-environment was used. The results show that for air-entrained concrete with fly ash or GGBS both prolonging the exposure to 65 % RH and exposure to CO2 diminishes the salt-frost resistance. The influence increases with increasing amount of fly ash or GGBS. However, the type of cement also has a certain influence. The influence of exposure to CO2 on the salt-frost resistance of concrete without entrained air was totally different from the influence on concrete with entrained air.

scholarly journals An Experimental Programme on Frc with Opc, Flyash, Ggbs, and Metakaolin

2019 ◽  
Vol 8 (10) ◽  
pp. 3713-3717
Keyword(s):  
Fly Ash ◽  
Fiber Reinforced Concrete ◽  
Mineral Admixtures ◽  
Test Results ◽  
River Sand ◽  
Split Tensile Strength ◽  
Manufactured Sand ◽  
Granulated Blast Furnace Slag ◽  
Strength Tests ◽  
Lime Stone

The production of Ordinary Portland Cement (OPC) is increasing year by year world over. Further, the production of every tonne of OPC generates one tonne of green house gases, (CO2 ) which results in Global Warming. Usage of OPC is more in construction industry as it is a major ingredient in Concrete. As the usage of Concrete is increasing year by year, more and more is the OPC production and hence the environment is getting polluted; added to this undesirable scenario, the natural resources like lime stone used to manufacture cement and river sand are getting depleted year by year. In order to prevent the usage of large amounts of OPC in Concrete, mineral admixtures like Ground Granulated Blast furnace Slag (GGBS), Fly Ash and Metakaolin which are pozzolanic and cementitious in nature are adopted to replace certain percentages of OPC. Manufactured Sand (M-sand) is adopted to replace river sand. Experimental investigation is conducted on fiber reinforced concrete with steel fibers @1% of weight of binder by casting requisite number of cubes and cylinders of concrete of grade M25; in these mixes OPC is replaced with GGBS, Fly Ash and Metakaolin up to 45%. Mechanical properties are determined by conducting compressive strength and split tensile strength tests; additionally some of the durability properties are established by conducting Water absorption and Sorptivity tests. Test results are comparable between controlled concrete and innovative concrete of present investigation.

Variasi Penambahan Sika Cim Dan Fiber Kawat Pada Beton Mutu Fc’ 30 Mpa

2018 ◽  
Vol 9 (2) ◽  
pp. 67-73
Author(s):  
M Zainul Arifin
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Curing Temperature ◽  
Test Results ◽  
Concrete Compressive Strength ◽  
Normal Concrete ◽  
Astm Method ◽  
Additive Type ◽  
Composition Variation ◽  
Compressive Strength Of Concrete

This research was conducted to determine the value of the highest compressive strength from the ratio of normal concrete to normal concrete plus additive types of Sika Cim with a composition variation of 0.25%, 0.50%, 0.75%, 1.00%, 1.25%, 1 , 50% and 1.75% of the weight of cement besides that in this study also aims to find the highest tensile strength from the ratio of normal concrete to normal concrete in the mixture of sika cim composition at the highest compressive strength above and after that added fiber wire with a size diameter of 1 mm in length 100 mm with a ratio of 1% of material weight. The concrete mix plan was calculated using the ASTM method, the matrial composition of the normal concrete mixture as follows, 314 kg / m3 cement, 789 kg / m3 sand, 1125 kg / m3 gravel and 189 liters / m3 of water at 10 cm slump, then normal concrete added variations of the composition of sika cim 0.25%, 0.50%, 0.75%, 1.00%, 1.25%, 1.5%, 1.75% by weight of cement and fiber, the tests carried out were compressive strength of concrete and tensile strength of concrete, normal maintenance is soaked in fresh water for 28 days at 30oC. From the test results it was found that the normal concrete compressive strength at the age of 28 days was fc1 30 Mpa, the variation in the addition of the sika cim additive type mineral was achieved in composition 0.75% of the cement weight of fc1 40.2 Mpa 30C. Besides that the tensile strength test results were 28 days old with the addition of 1% fiber wire mineral to the weight of the material at a curing temperature of 30oC of 7.5%.

scholarly journals Practical Prediction Models of Tensile Strength and Reinforcement-Concrete Bond Strength of Low-Calcium Fly Ash Geopolymer Concrete

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 875
Author(s):  
Chenchen Luan ◽  
Qingyuan Wang ◽  
Fuhua Yang ◽  
Kuanyu Zhang ◽  
Nodir Utashev ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Fly Ash ◽  
Bond Strength ◽  
Prediction Models ◽  
Splitting Tensile Strength ◽  
Geopolymer Concrete ◽  
Structural Factors ◽  
Test Results ◽  
Portland Cement Concrete ◽  
Low Calcium

There have been a few attempts to develop prediction models of splitting tensile strength and reinforcement-concrete bond strength of FAGC (low-calcium fly ash geopolymer concrete), however, no model can be used as a design equation. Therefore, this paper aimed to provide practical prediction models. Using 115 test results for splitting tensile strength and 147 test results for bond strength from experiments and previous literature, considering the effect of size and shape on strength and structural factors on bond strength, this paper developed and verified updated prediction models and the 90% prediction intervals by regression analysis. The models can be used as design equations and applied for estimating the cracking behaviors and calculating the design anchorage length of reinforced FAGC beams. The strength models of PCC (Portland cement concrete) overestimate the splitting tensile strength and reinforcement-concrete bond strength of FAGC, so PCC’s models are not recommended as the design equations.

scholarly journals Phase Transformation of Kaolin-Ground Granulated Blast Furnace Slag from Geopolymerization to Sintering Process

2021 ◽  
Vol 7 (3) ◽  
pp. 32
Author(s):  
Noorina Hidayu Jamil ◽  
Mohd. Mustafa Al Bakri Abdullah ◽  
Faizul Che Pa ◽  
Mohamad Hasmaliza ◽  
Wan Mohd Arif W. Ibrahim ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Room Temperature ◽  
Curing Temperature ◽  
Curing Process ◽  
Sintering Process ◽  
Granulated Blast Furnace Slag ◽  
Fluxing Agent ◽  
Furnace Slag

The main objective of this research was to investigate the influence of curing temperature on the phase transformation, mechanical properties, and microstructure of the as-cured and sintered kaolin-ground granulated blast furnace slag (GGBS) geopolymer. The curing temperature was varied, giving four different conditions; namely: Room temperature, 40, 60, and 80 °C. The kaolin-GGBS geopolymer was prepared, with a mixture of NaOH (8 M) and sodium silicate. The samples were cured for 14 days and sintered afterwards using the same sintering profile for all of the samples. The sintered kaolin-GGBS geopolymer that underwent the curing process at the temperature of 60 °C featured the highest strength value: 8.90 MPa, and a densified microstructure, compared with the other samples. The contribution of the Na2O in the geopolymerization process was as a self-fluxing agent for the production of the geopolymer ceramic at low temperatures.

Effects of Nano-CaCO3 on the Compressive Strength and Microstructure of High Strength Concrete in Different Curing Temperature

2011 ◽  
Vol 121-126 ◽  
pp. 126-131 ◽  
Author(s):  
Qing Lei Xu ◽  
Tao Meng ◽  
Miao Zhou Huang
Keyword(s):  
Compressive Strength ◽  
Low Temperature ◽  
High Strength Concrete ◽  
High Strength ◽  
Curing Temperature ◽  
Test Results ◽  
Strength Concrete ◽  
Calcium Nitrite ◽  
Orientation Index ◽  
Early Strength

In this paper, effects of nano-CaCO3 on compressive strength and Microstructure of high strength concrete in standard curing temperature(21±1°C) and low curing temperature(6.5±1°C) was studied. In order to improve the early strength of the concrete in low temperature, the early strength agent calcium nitrite was added into. Test results indicated that 0.5% dosage of nano-CaCO3 could inhibit the effect of calcium nitrite as early strength agent, but 1% and 2% dosage of nano-CaCO3 could improve the strength of the concrete by 13% and 18% in standard curing temperature and by 17% and 14% in low curing temperature at the age of 3days. According to the XRD spectrum, with the dosage up to 1% to 2%, nano-CaCO3 can change the orientation index significantly, leading to the improvement of strength of concrete both in standard curing temperature and low curing temperature.

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