Rapid Chloride Permeability Test Research Articles

Cementing efficiency factors of ceramic polishing residue in compressive strength and chloride resistance of mortar

During the polishing process of ceramic tiles, plenty of ceramic polishing residue (CPR) is generated. In order to evaluate the reutilization of CPR as a supplementary cementitious material (SCM) in mortar/concrete, and investigate its effects on the strength and durability, a series of mortar mixes containing different CPR contents were made for conducting compressive strength test and rapid chloride permeability test. It was found that adding CPR as a SCM up to 20% could still markedly improve the compressive strength and chloride resistance, while at the same time reduce the waste disposal, cement consumption and carbon footprint for sustainable development. Moreover, the cementing efficiency factor of the CPR in 28-day compressive strength was generally higher than 1.5 whereas that in chloride resistance was generally higher than 4.0, indicating that the CPR is a highly effective SCM for replacing part of the carbon-intensive cement and improving the strength and durability performance.

Durability characteristics of self-compacting concrete made with copper slag

In this paper, research was conducted to investigate the performance of copper slag in self-compacting concrete (SCC) pertaining to fresh and hardened properties. In this study, natural sand was substituted with 0–60% copper slag giving an increment of 10%, cement content was replaced with 20% fly ash and rest all other parameters including the w/c ratio and amount of super plasticiser remained constant. Fresh properties included the test for passing ability, flowability and the viscosity of SCC. Compressive strength was conducted to test the mechanical property of SCC. Water absorption, rapid chloride permeability and sorptivity test were considered to assess the durability aspects of SCC for up to 1 year. To validate the experimental results, linear regression was applied to develop correlations between fresh, strength and durability properties. The scanning electron microscopy technique was used to study the microstructure of concrete besides X-ray diffraction analysis and energy dispersive spectroscopy. Method of Analysis of variance (ANOVA) was determined to study the statistical significance of the test results of compressive strength and durability properties of SCC. The fresh properties enhanced as the amount of copper slag increased. The results of compressive strength and durability indicated a significant increase in SCC mixes containing up to 30% copper slag; beyond which the results were analogous to that of control concrete mix. This study suggested that copper slag is a sustainable material which could be used in SCC mixes.

Field Validation of Concrete Transport Property Measurement Methods.

Reinforcing steel corrosion, caused by chloride ingress into concrete, is the leading cause of reinforced concrete deterioration. One of the main findings in the literature for reducing chloride ingress is the improvement of the durability characteristics of concrete by the addition of supplementary cementitious materials (SCMs) and/or chemical agents to concrete mixtures. In this study, standard ASTM tests—such as rapid chloride permeability (RCPT), bulk diffusion and sorptivity tests—were used to measure concrete properties such as porosity, sorptivity, salt diffusion, and permeability. Eight different mixtures, prepared with different SCMs and corrosion inhibitors, were tested. Apparent and effective chloride diffusion coefficients were calculated using bound chloride isotherms and time-dependent decrease in diffusion. Diffusion coefficients decreased with time, especially with the addition of SCMs and corrosion inhibitors. The apparent diffusion coefficient calculated using the error function was slightly lower than the effective diffusion coefficient; however, there was a linear trend between the two. The formation factor was found to correlate with the effective diffusion coefficient. The results of the laboratory tests were compared and benchmarked to their counterparts in the marine exposure site in the Arabian Gulf in order to identify laboratory key tests to predict concrete durability. The overall performance of concrete containing SCMs, especially fly ash, were the best among the other mixtures in the laboratory and the field.

Arrowroot as bio-admixture for performance enhancement of concrete

With the aim to promote sustainability by resorting to natural renewable resources, the potential of arrowroot (starch) as an admixture in cement concrete system was evaluated in this study. Arrowroot has a polymer structure as most of the chemical admixtures and it showed considerable effects on the setting time of cement, workability and durability of concrete. Unlike chemical admixtures, it has no consequent degrading effect on the environment. In this study arrowroot was added by 0.5%, 1%, 1.5% and 2.5% to cement weight. The addition showed delayed setting time of paste and increased workability of fresh mix for concrete. A better workability led to a better mixing of the constituents that resulted in better durability. Durability parameters were enhanced for concrete with arrowroot admixtures as confirmed by sorptivity, rapid chloride permeability test (RCPT) and rapid migration test (RMT) at 120 days of curing. A closer look to the microstructure of mortar via scanning electron microscopy (SEM) imaging of specimen without and with admixture revealed the effects of arrowroot in terms of pore structure and proportion of hydration products present. However, these effects are dose dependent. This study recommends arrowroot as a set retarding and workability enhancing bio-admixture and the optimum dose is suggested to be within 1%–1.5% of cement content.

Strength and Durability Properties by Replacement of Natural Zeolite and Fly ash in Ordinary Portland Cement

Natural zeolite and Flyashresidue, a sort of hydrated Alumino-Silicate is used amply as ordinary pozzolanic material in particular areas of the world. In this calculation, the suitability of a secretly quarried zeolite and mineral admixture called fly ash is used for getting better mechanical and durability property of bond. The presentation of strong quality was better with a dissimilar degree of zeolite and fly ash was examined. The substitution on zeolite and fly ash with other proportions like 10% zeolite with ordinary Portland cement (OPC), 10% zeolite and 10% fly ash, 10% zeolite and 20% fly ash, 10% zeolite and 30% fly ash for M25 grade of concrete and done valuations with mechanical properties such as compressive strength, split tensile test, water permeability test, rapid chloride permeability test. By differentiating these effects between a run of the mill concrete and dissimilar degrees of Zeolite and Flyash.By comparing these results between normal concrete with different proportions of Zeolite and Flyash.

The effect of chloride ion diffusion on corrosion activity of kaolin geopolymer paste in artificial seawater

This paper presents the effect of chloride ion diffusion on the corrosion activity of kaolin geopolymer paste in artificial seawater. An aluminosilicate material that rich with aluminium and silicon such as kaolin is selected as a raw material in the geopolymerization of geopolymer. Kaolin then mixed with an alkaline activator that consist mixture of sodium hydroxide (NaOH) solution with sodium silicate (Na2SiO3) solution. Two types of samples are used in this study, which 7 days and 14 days sample. A few testing is conducted in order to test the chloride ion diffusion on the samples such as Rapid Chloride Permeability Test, Rapid Migration Test and Salinity Test. The result shows that sample for 7 days consist the higher penetration of chloride ion compare sample of 14 days. This is proven with the result of salinity. A longer curing time of the sample cause a lesser penetration of Cl− ion.

Experimental Research on Strength Properties of Concrete (M60) Partially Fine Aggregate Replaced with Waste Crushed Glass.

Due to increased construction practices there was a very high demand in consumption of raw materials that are to be used in concrete. In the raw materials, sand is one of the major construction materials that is consumed adequately. It’s presence will be vanished due to excessive digging .The effect will be to the nearby localities .As well the stability hydraulic structures nearby river banks will be affected with this. To reduce digging practices the fine aggregate was partially replaced with waste crushed glass in 0%,10%,20%,30% andv40% along with 0.25%Super plasticizer SP 430 to achieve workability. The crushed glass is non-biodegradable and cannot be disposed off, also causes several environmental effects. By utilizing this waste as a useful material in the form as replacing material of fine aggregate we can reduce the waste content and in the same way it can be used as a resource. In order to check the concrete strength and durability tests like Compressive strength test, Split tensile strength test, Flexural strength test for 7,14,28 days curing and acid attack test, rapid chloride permeability test, Abrasion tests were conducted. SEM tests are also conducted on concrete with replaced fine aggregate. The current research work describes the proper utilization of waste crushed glass as a useful construction material.

Durability Assessment of Concrete with Class-F Fly Ash by Chloride Ion Permeability

This paper discusses on Rapid Chloride Permeability Test investigations on penetration of chloride ions included with replacement of cement by flyash material. By weigth of cement, the fly ash content is replaced from 0% to 60%. Concrete mixes with different binder content varies from 350, 400 and 450 kg/m3 were proportioned with different water binder(w/b) ratios = 0.4, 0.45 and 0.50. Specimens were casted and tested for 28 days. For all the combinations, RCPT was carried out and the charge passed through the specimens was noted. Rapid Chloride Permeability Test value of concrete without fly ash was found to be more than the concrete with fly ash. The Rapid Chloride Permeability Test values are found to be decreased if the percentage of flyash increases. The reason could be the pozzolanic reaction products (CSH) fill the pores between the cement pastes and cause a denser concrete matrix, resulting in better durability. Hence, it can be suggested that the fly ash concrete up to 50% replacement can be used for variety of applications.

Burnt Clay Brick Aggregate for Internal Curing of Concrete under Adverse Curing Conditions

In this study, properties of concrete with brick aggregate as internal curing medium has been investigated under adverse curing conditions. Brick aggregates, commonly known as brick chips (BC), have high porosity and absorption capacity. Desorption tests of different sizes of BC revealed that BC could desorb about 90% of its absorbed water. It was also observed that smaller size BC had higher desorption capacity than that of larger ones. Moreover, higher internal relative humidity was observed for all internally cured (IC) samples as compared to control samples made with 100% rock aggregate particles commonly known as stone chips (SC). Internally cured samples with three different percent replacements (15%, 20% and 25%) of SC with BC were prepared and subjected to six simulated adverse curing conditions. The performance of internally cured concrete under different curing conditions was evaluated in terms of compressive strength, rapid chloride permeability test (RCPT) and linear shrinkage test. The internally cured samples exhibited higher strength and less permeability and shrinkage as compared to their control counterparts under all adverse curing conditions considered in the study. Based on the findings of the study, 20% partial replacement of SC with BC of 9.5 mm in size can be recommended as a guideline for producing internally cured concrete under adverse curing conditions.

Hydrophilic and hydrophobic chemicals as self curing agents in self compacting concrete

In recent years, there has been an increase in the study of providing internal curing in concrete to enable high water retention capacity. Curing is an important parameter that directly affects the strength and durability of concrete. The present experimental program evaluates the effect of hydrophilic and hydrophobic chemicals as self curing compounds in Self Compacting Concrete (SCC). The parameters in this study include type of curing chemical (Polyethylene Glycol - 4000, Liquid Paraffin Wax), dosage of curing chemical (0%, 0.1%, 0.5% and 1.0%) and curing temperature (Room temperature −27±2 °C, elevated temperature-60 °C). The performance of curing chemicals was determined by conducting tests viz: compressive strength, split tensile strength, flexural strength and rapid chloride permeability test (RCPT). It was concluded that both curing chemicals performed better at both curing temperature conditions compared to no cured specimen. The study concluded that the optimum dosage of Polyethylene Glycol and Liquid Paraffin Wax is 1.0% and 0.1% by weight of cement.

The Influence of Marine Algae on the Mechanical Properties of Concrete.

Concrete dependent on Portland cement is most generally utilized construction material on the planet, and its generation pursues a pattern of development. About 15% of the all-out concrete creation contains synthetic admixtures, which are chemicals added to concrete, mortar or grout at the moment of blending to change their properties, either in fresh or solidified state. Algae are photosynthetic amphibian plants that use inorganic supplements, for example, nitrogen and phosphorus. Around 71% of the world is encompassed by sea, the marine green growth naturally known as seaweeds are a differing gathering of photoautotrophic living beings of different shapes (filamentous, lace like, or plate like) that contain pigments, for example, chlorophyll, carotenoids, and xanthophyll's. It controls the substance response of Cement. It maintains a strategic distance from voids and decline porousness of the solid. To study the strength of marine brown algae concrete different percentages (5%, 10% &15%) of algae are added with cement content to determine the Compression strength , Split Tensile strength concrete ,Shrinkage test and Rapid chloride permeability test for M25, M35 & M40grades of concrete. The Slump of the marine algae concrete is increased as the percentage of Wet Marine Brown algae increases and decrease when compared with the conventional concrete and dry marine algae concrete. The concrete compressive strength is decreased with expanding 15 level of the Wet Marine Brown algae replacement to the conventional concrete and dry marine brown algae concrete. The Split Tensile strength was reduced by 15% Wet Marine Brown algae when compared with conventional concrete.

Effect of nano-silica on mechanical properties and durability of self-compacting mortar containing natural zeolite: Experimental investigations and artificial neural network modeling

In this paper, durability and mechanical properties of self-compacting mortars containing various percentage of natural zeolite and nano-silica were assessed experimentally using compressive and flexural strength, water absorption, electrical resistivity and rapid chloride permeability tests. The results showed that the mechanical properties of self-compacting mortars would be increased by increasing the replacement levels of natural zeolite and nano-silica. Addition of natural zeolite and nano-silica increased the electrical resistivity of self-compacting mortars and consequently decreased the permeability of the self-compacting mortars. The chloride ion penetration into self-compacting mortars were decreased by increasing natural zeolite and nano-silica contents. It was also observed that the presence of the pozzolan and nano material has a positive influence on the microstructural properties and hydration process of self-compacting mortars. Additionally, the artificial neural network modeling could efficiently predict the durability mechanical properties of self-compacting mortars.

Durability of Concrete Mixtures Containing Supplementary Cementitious Materials in Rapid Chloride Permeability Test

Durability of Concrete Mixtures Containing Supplementary Cementitious Materials in Rapid Chloride Permeability Test

Investigation of SCC characterizations incorporating supplementary cementitious materials

An experimental study was performed to assess the effect of metakaolin (MK) as supplementary cementitious material (SCM) and limestone powder (LP) and nano-titanium dioxide (nano-TiO2; NT) as mineral admixtures on the pore structure, mechanical and durability of self-compacting concrete (SCC). The fresh-state performance was evaluated by slump flow, T 50, V-funnel and L-box tests, and hardened-state parameters were analyzed through compressive strength, water absorption, density and electrical resistivity. Furthermore, permeability was analyzed by means of the rapid chloride permeability test and mercury intrusion porosimetry. Using additives resulted in improvement of rheological properties and compressive strength. Additionally, the density and electrical resistivity of SCC mixes containing SCMs and NT were higher than those of the control SCC mixes. Low absorption and permeability values were obtained for the mixes containing 5% NT. The results herein reported suggest that replacement ratios of 15% MK, 10% LP and 5% NT can be considered as optimal from a cost–benefit point of view in terms of fresh- and hardened-state performance. Predictive models for the hardened properties analyzed have been obtained using artificial neural networks (ANNs). ANNs have been proven an appropriate alternative method for predicting the hardened properties of SCC mixes.

Fracture and permeability properties of glass fiber reinforced self-compacting concrete with and without nanosilica

This article studied the influence of utilizing nanosilica (NS) and glass fiber (GF) on mechanical and permeability properties of self-compacting concrete (SCC) with fly-ash blended. There were three SCC series designed. This study had a constant amount of water-to-binder (w/b) ratio and total binder content which is 0.35 and 550 kg/m3, respectively. This study utilized three different percentages of nanosilica to replace cement. These percentages were 0%, 2%, and 4% by weight, respectively. The incorporation of fly ash (FA) was done by using 25% of total binder content by weight in all the SCC mixtures. Moreover, glass fiber was used as an additive material with levels of 0%, 0.35%, 0.70%, 1.0%, and 1.5%, respectively. To experimentally evaluate mechanical properties; compressive strength; static modulus of elasticity; splitting tensile strength; fracture energy, and the permeability properties of the mixtures; sorptivity index; rapid chloride permeability test (RCPT); gas permeability test were done. The results showed that with utilizing nanosilica which ranged from 0% to 4% with replacement up until 0.7% glass fiber, indicated to enhance the mechanical and permeability properties of self-compacting concrete.

Compressive strength, pore structure and chloride transport properties of alkali-activated slag/fly ash mortars

The effects of silicate modulus, alkali dosage, fly ash content and steam curing on compressive strength, pore structure and chloride transport properties of alkali-activated slag/fly ash (AASF) mortars have been investigated. The results showed that steam curing exhibited little influences on compressive strength and chloride transport properties of AASF mortars. The compressive strengths of AASF mortars increased with the increase of silicate modulus, alkali dosage, and decreased with the increase of the fly ash content due to the changes of pore structure within the range of 10–104 nm. The decrease of both chloride migration coefficient from the rapid chloride migration (RCM) test and passed charge from the rapid chloride permeability (RCP) test of AASF mortars were observed with the increase of silicate modulus and decrease of fly ash content due to the improvement of their pore structure in the aforementioned range. However, inconsistent results between RCM and RCP tests were observed with the increase of alkali dosage. The immersion of the AASF mortars in water decreased their passed charge due to the ion leaching out from their pore solution. The increase of water-to-specimen ratio increased the amount of leached substance and decreased the passed charge, but showed no effect on their chloride migration coefficient. Thus, RCM test is more suitable for characterization of chloride transport properties of alkali-activated materials than RCP test.

Cementing efficiencies and synergistic roles of silica fume and nano-silica in sulphate and chloride resistance of concrete

It has been proven by various studies that adding silica fume (SF) alone or nano-silica (NS) alone can provide significant beneficial effects on the durability of concrete. In theory, SF and NS may also be added together, but up to now, such possible combined usage of SF and NS for improving the durability of concrete, especially the sulphate and chloride resistance, has not been deeply explored. In this paper, the individual and synergistic roles of SF and NS in the sulphate and chloride resistance of concrete were investigated by producing a series of concrete mixes containing varying SF, NS and water contents for strength test, sulphate attack test and rapid chloride permeability test. It was found that the combined addition of SF and NS can further enhance the sulphate and chloride resistance to higher than possible with the single addition of SF or NS. From the experimental results, the cementing efficiencies of SF and NS were evaluated, from which it was revealed that there exist certain synergistic effects offered by the combined addition of SF and NS on the sulphate and chloride resistance.

Effects of Silica Fume on the Performance of Cemented Paste Backfill Mixed with Brine

Brine water as a filling affected the strength of the filling body in Sanshandao Gold Mine, because it introduced higher concentrations of Cl−, SO42−, Mg2+ and other ions. In this paper, the effect of brine on the strength of cemented paste backfill and the mechanisms of micro-corrosion were studied. The effect of silica fume on the corrosion resistance of brine ions in cemented paste backfill was also studied. The influence of bittern ions on cemented paste backfill was analyzed using scanning electron microscopy and X-ray diffraction. Chloride permeability, capillarity coefficient, shear stress and viscosity and shear rate are obtained through the capillary water absorption test, rapid chloride permeability test, compressive strength test, direct shear test, and rheological test of cemented paste backfill. Then the mechanism for improving the brine corrosion resistance of the filling body with silica fume was analyzed. The results show that there was an improvement in the bittern corrosion resistance and other properties of the cemented paste backfill when the content of silica fume was 8% by weight.

Effects of Modified Metakaolin Using Nano-Silica on the Mechanical Properties and Durability of Concrete.

This paper discussed the effects of modified metakaolin (MK) with nano-silica (NS) on the mechanical properties and durability of concrete. In the first phase, trial mixes of concrete were prepared for achieving the desired value of the 28 days compressive strength, and the charge passed in rapid chloride permeability test (RCPT). In the second phase, statistical analysis was performed on the experimental results using the response surface method (RSM). The RSM was applied for optimizing the mix proportions for the required performance by exploiting the relationship between the mix characteristics and the corresponding test results. A blend of 10% MK + 1% NS as part of cement replacement exhibited the highest mechanical properties and durability characteristics of concrete; concrete mix showed that the 28-days compressive strength (CS) was 103 MPa, which was 15% greater than the CS of the control mix without MK or NS. The same mix showed more than 40% higher flexural and split-tensile strength than the control mix; also it resulted in a reduction of 73% in the rapid chloride permeability value. ANOVA technique was used for optimizing the nano-silica and metakaolin content for achieving maximum compressive strength and minimum RCPT value. Statistical analysis using ANOVA technique showed that the maximum compressive strength and lowest RCPT value could be achieved with a blend of 10% MK and 1.55% NS.

Effect of Alccofine and GGBS Addition on the Durability of Concrete

Portland cement is the most important ingredient of concrete. A large scale production of cement plant consume large amount of energy and produce a number of undesirable products ( which negatively affect the environmental and depletion of natural resources. This treat to ecology has to lead to researchers to use industrial by-products as supplementary cementitious material in making concrete. In view this silica fume (SF), ground granulated blast furnace slag (GGBS), rice husk ash, fly ash (FL), metakolin, alccofine (AL), micro fine material, etc.; are tried out for replacing cement partially or fully in concrete, without compromising on its strength, also reduce greenhouse gases and sustainable way of management of waste. A new ultra-fine material emerged in market is called alccofine. This is available as a cementious material for replacing cement. Since this a new material, a study is tried out with the combination of Alccofine and GGBS. Ordinary Portland Cement 53 grade was used throughout the study and the grade of concrete is M20. Totally 108 cubes and 27 cylinder were cast and tested in the laboratory with nine different percentage combination of alccofine (A), GGBS (G) and cement (C) (C100, C70A0G30, C90A10G0, C60A10G30, C30A10G30, C40A0G60, C85A15G0, C55A15G30, C25A15G60). Each case 3 nos. of specimen were used for repeatability. It is intended to study the compressive strength, and its durability properties like acid attack test, sulphate attack test and rapid chloride permeability test (RCPT). Among the nine different combination the maximum compressive strength of concrete is achieved by using AL10% and GGBS 30% is 38.08 N/mm2. C60A10G30 is 28.76% higher than the control mix. Result shows that concrete incorporating alccofine and GGBS have higher compressive strength and alccofine enhanced the durability of concrete also.