Water Penetration Depth Research Articles

Investigations on Mechanical Characteristics and Microstructural Behavior of Laterized High Strength Concrete Mix

The present research focuses on the varying proportion of lateritic fine aggregates in High strength concrete (HSC). Concrete mixes of M60 grade were produced by replacing manufactured sand with laterite in the ratio of 25 to 100 percent (by weight), and properties of the mixes are studied. To attain high strength mix, 10% micro silica and 10% of fly ash (FA) were added to all mixes. Mechanical properties were studied after 7, 28, 56, and 90 days of curing, and laterized specimens achieved approximately 12 percent higher compressive strength than control specimens, whereas the split-tensile and flexural strengths increased up to 11.14% and 12.83%, respectively. The results indicated that 25% substitution of laterite was the optimum percentage in HSC concrete. Microstructural studies of optimum mix and reference mix were conducted at 28 days to better morphological and mineralogical understanding of the laterized HSC. Durability parameters such as water penetration depth, chloride ion permeability, and sorptivity exhibited higher values for laterite mixes than the control mixes. The flexural behavior of Reinforced HSC beams using lateritic aggregates was investigated, and the load-carrying capacity of laterized beams was reported to be 11.3 percent higher than control beams. The study results indicate that HSC can be achieved with partial substitution with lateritic fine aggregates and proves that laterite can replace conventional aggregates.

The Effect of Crystalline Waterproofing Admixtures on the Self-Healing and Permeability of Concrete.

This paper investigates the effectiveness of a specific crystalline waterproofing admixture (CWA) in concrete as a function of a water–binder ratio. Four concrete mixes with and without CWA were prepared; two of them with a water–binder ratio of 0.45 and two of them with a water–binder ratio of 0.55. Water permeability and compressive strength were tested on hardened concrete specimens and self-healing of cracks over time was observed. Cement paste and CWA paste were prepared to clarify the results obtained on the concrete specimens. SEM and EDS and XRD and FTIR were performed on the hardened pastes to explain the mechanism of CWA working. The results show that the addition of CWA had no significant effect on the compressive strength of the concrete, but reduced the water penetration depth in the concrete, and the reduction was more effective for mixes with lower water–binder ratio. Regarding the self-healing effect, it can be concluded that the addition of CWA improves the crack healing in concrete, but the efficiency of self-healing is highly dependent on the initial crack width. The mechanisms involved in the reduction of water penetration depth and crack healing in concrete can be explained by different mechanisms; one is creation of the CSH gel from unreacted clinker grains, then formation carbonate, and additional mechanism is gel formation (highly expansive Mg-rich hydro-carbonate) from magnesium based additives. The presence of sodium silicate, which would transform into carbonate/bicarbonate, also cannot be excluded.

Sustainable concrete: Potency of sugarcane bagasse ash as a cementitious material in the construction industry

The aim of this research is to determine the mechanical and durability properties of sugarcane bagasse ash (SCBA) as a partial replacement to Ordinary Portland Cement (OPC) in concrete. The SCBA was partially replaced at the percentage of 5 %, 10 %, 15 % and 20 % by weight of cement for a mean target strength of 27 MPa. A slump range of 130–150 mm was maintained constant throughout the experiment procedures. A total of 120 cubes and 30 rectangular beams were tested and the results were compared with control concrete. To evaluate the behaviour of SCBA on concrete, different tests were conducted on the concrete specimens namely, compressive strength, flexural strength, water absorption, water penetration, carbonation and ultrasonic pulse velocity. The results demonstrated that at 120 days of curing, compressive strength increased by 2.6 % and 1.7 % for 5 % and 10 % replacement level. The water absorption increased by 255 %, 390 %, 438 % and 488 % for 5 %, 10 %, 15 % and 20 % replacement level. The other tests showed decreased flexural strength and ultrasonic pulse velocity and increased water penetration and carbonation depth. The study inferred that 10 % replacement of OPC by SCBA exhibited positive performances and can be considered a suitable cementitious material in the construction industry.

Investigation of Mechanical and Permeability Properties of Fiber Mortars

Concrete is a brittle material which has a higher compressive strength compared to its tensile strength. Steel, glass or polymer fibers are usually added to concrete in order to improve the ductility under mechanical loads. One of the most important factors taken into consideration in producing a durable concrete is by imperviousness concrete. In this study, the mechanical and permeability properties of fiber reinforced mortars were investigated. For this purpose, in addition to the reference, 0.1%, 0.2% by volume, glass fiber reinforced and 1.15% and 2% impermeability admix incorporated series were prepared. The effective water/cement ratio of all produced mortar samples was determined to be 0.5. The workability, ultrasonic pulse velocity (UPV), flexural strength, compressive strength, splitting tensile strength, determination of water penetration depth under pressure were determined in all series. According to the test results, as the glass fiber ratio increased, the water penetration depth decreased by 15% compared to the reference. In the series where 0.2% glass fiber was used, there was a 20% increase compared to the reference in terms of splitting tensile strength. In addition, there is an increase in splitting tensile strength in series produced using glass fiber and impermeability additive.

Sustainable alkali activated concrete with fly ash and waste marble aggregates: Strength and Durability studies

This study examines the use of waste marble aggregates (WMA) as a substitute to natural aggregates (NA) to produce sustainable alkali activated concrete (AAC). Sodium hydroxide (NaOH) of 8M concentration and sodium silicate (Na2SiO3) were used as an alkaline activator for high calcium fly ash based AAC. NA were replaced with WMA at different weight ratios, namely 0%, 25%, 50%, 75% and 100%. Different properties like density, workability, air content, compressive, flexural and tensile strengths, along with modulus of elasticity of fresh and hardened concrete were investigated. Also, rapid chloride penetration test, oxygen permeability index test, depth of water penetration, electrical resistivity and acid resistance were also conducted to study the durability characteristics of the sustainable AAC. Results of this study showed that WMA affected the pore structure and new calcium-based products were formed along with polymeric products. New products in the matrix accelerate the polymerisation process and significantly enhanced the strength properties and durability of AAC. The outcomes of this study revealed that WMA can be employed to replace up to 50% of NA in the production of sustainable AAC. Its high potential to replace NA could lead to significant saving in energy, cost and, can further reduce the hazardous environmental impacts caused by marble industries during mining, processing and polishing phases.

Evaluating durability parameters of concrete containing limestone powder and slag under bacterial remediation

Microbiological methods, in which bacteria serve as catalysts and contribute to urea hydrolysis by producing the urease enzyme, can be used to enhance concrete durability and repair the entrained pores and micro-cracks. The hydrolysis of urea in a calcium-rich environment leads to the formation of solid calcium carbonate that fills concrete pores and cracks. At least 7% of the total carbon dioxide available on a global scale originates from cement production. This has encouraged efforts to decrease cement consumption in concrete structures and to replace it with such cement-like materials as fly ash, blast furnace slag, micro silica, or limestone powder. Slag and fine limestone have nowadays gained wide applications as cement replacements for their technical, economic, and environmental advantages. The present study was designed and implemented to investigate concrete durability, water absorption, carbonation depth, and water penetration depth in specimens containing slag and fine limestone powder in their concrete mixes, where exposed to the bacterial treatment. For this study, 78 concrete cubes of 100 mm in size, 78 cubes of 70 mm, and 78 prisms of 120 × 200 × 200 mm3 were made using six concrete mix designs containing two limestone powder ratios of 0 and 15% and three slag ratios of 0, 20, and 40% as replacements for cement. The specimens were subsequently treated for 28 days in one of the curing media of tap water, seawater, and a solution of calcium lactate and urea. Finally, the surfaces of the specimens were treated for two weeks in one of the above media. Results showed improved durability in both concrete specimens with bacteria in their mix designs and those subjected to surface treatment with bacteria. Moreover, all the specimens with bacteria recorded lower values of water absorption, carbonation, and water penetration depths than those lacking bacteria. As regards the cement replacement materials, it was found that limestone powder served as a source of calcium for bacteria and that slag enhanced the compressive strength of concrete and reduced its permeability. Finally, the solution of calcium lactate and urea from among the curing media investigated was found to have better effects on the specimens either containing bacteria in their mix designs or subjected to surface remediation with bacteria.

Hydrochemistry and geothermometry of thermal waters from UAE and their energetic potential assessment

Two main low-enthalpy geothermal fields are present in the UAE: Mubazzarah-Ain Faidha (Al-Ain city) in the Abu Dhabi Emirate and Ain-Khatt in the Ras Al-Khaimah (RAK) Emirate. The chemistry of nineteen waters was analyzed to calculate geothermal reservoir temperatures using cation and silica geothermometers, and to describe the source of recharge of the hot waters from isotopic data. In total, 19 water samples (16 from wells, 2 from springs AF and KT1 and one sea water) were collected and analyzed for major anion and cation concentrations. The isotope and chemical data suggest that the hot waters from Al-Ain (Mubazzarah and Ain Faidha) are almost entirely recharged by rainwater, which originates at higher altitude, heats up through deep water circulation, and travels to the surface through fault structures within the study area. The waters are mainly Na-Cl type, and the discharge temperatures range from 32.5 °C to 49 °C. The Na-K geothermometers predict a geothermal reservoir temperature of 151 °C for the Mubazzarah-Ain Faidha hot waters and 112 °C for the Ain-Khatt hot waters with estimated depth of water penetration of 3.8 km and 2.6 km, respectively. The existing known geothermal resources in the Mubazzarah and Ain Khatt areas can be immediately and sustainably used for low-temperature, direct-use geothermal applications. A stochastic Monte Carlo simulation was performed to estimate the geothermal energy stored in the two main low-enthalpy geothermal fields for 25 years and 50 years. The geothermal electricity potential at Mubazzarah-Ain Faidha is ∼16.5 MWe and ∼8.27 MWe for 25 and 50 years, respectively. The geothermal electricity potential at Ain Khatt is ∼291 kWe and ∼146 kWe for 25 and 50 years, respectively. These preliminary potential assessments are subject to further delineation drilling and availability of field performance data and considered that the geothermal power plant has either a single or multiple ORC systems due to the very low temperature.

Water transport and shrinkage in concrete made with ground recycled concrete-additioned cement and mixed recycled aggregate

This article reports on analytical research into water transport in concrete with 10%–25% ground recycled concrete (GRC) as partial Portland cement replacement and 0% or 50% mixed recycled aggregate (MRA). It included analyses of durability indicators associated with water transport: effective (or open) porosity, penetration depth of water under pressure, permeability coefficient, capillary water absorption and electrical resistivity. Shrinkage was also monitored in all concrete samples. The findings showed that replacing up to 25% OPC with GRC induced a linear rise in effective porosity of up 11.4% in concrete with 100% NA and 33% in mixes with 50% MRA, relative to conventional concrete. The outcome, a tightly interconnected pore structure, lowered electrical resistivity by 14% in NA and 23% in MRA GRC-additioned cement concrete. That pore structure was nonetheless sufficiently impermeable to ensure suitable concrete durability, with penetration depth of water under pressure below 30 mm, a permeability coefficient below 10−12 m/s and sorptivity below 1 mm/h0.5. The three-way ANOVA conducted revealed that adding GRC was the factor with the greatest impact on penetration depth of pressurised water, permeability coefficient and sorptivity. Curing time was the most statistically significant factor for electrical resistivity and shrinkage in both mix families (NA and GRC), inasmuch as it determined the degree of hydration of the anhydrous phase in GRC and in the residual mortar bound to MRA components. Further to the present findings, the use of GRC at a replacement ratio of up to 10% does not lower recycled material concrete's durability relative to the mixes made with ordinary Portland cement.

Study of using micro‐nano bubble to improve workability and durability of self‐compact concrete

AbstractDeveloping self‐compacting concrete (SCC) with higher workability and durability properties by replacing mixing water with nano‐bubble without a decrease in mechanical strength is the purpose of this study. For this aim, different SCC mixtures were designed by using tap water and micro‐nano bubble and replacing silica fume, fly ash, slag, zeolite, and the mixture of fly ash and silica fume with cement. The workability, mechanical, and durability properties of the SCC mixture were tested according to ASTM and BS standards. In addition to air content test, for evaluation of the workability of SCCs, Slump flow in 10 and 60 min (for filling ability), V‐funnel, L Box, and J‐ring (for passing ability) were tested. For mechanical properties (compressive and tensile strength) and for durability of concretes (water penetration test and electrical resistivity) were tested. The workability test results indicate that using a micro‐nano bubble instead of tap water in different SCC mixture designs did not make a significant difference. But in hardened concretes, using the micro‐nano bubble increase the compressive and tensile strength of different concrete mixture designs except for SCC including fly ash and silica fume. Depth of water penetration and 30 min water adsorption for different concrete mix designs decreased compared to using tap water except for the sample contain zeolite, which increased slightly. Also, the permeability of concrete was tested by electrical resistivity. The results indicate that using the micro‐nano bubble decrease electrical resistivity and they were in the very low range (37–254 Ω‐m). The scanning electron microscope image confirmed in increasing mechanical and durability properties for a sample where used the micro‐nano bubble without pozzolans.

Effect of different expanded aggregates on durability-related characteristics of lightweight aggregate concrete

Lightweight aggregate concrete (LWAC) has relatively larger porosity than conventional concrete, mainly due to the incorporation of porous lightweight aggregates. The types of used lightweight aggregates are critical in determining the physical properties of LWAC, and it is therefore important to examine their effects on the durable characteristics of the material. To perform comparative analysis, the concrete mixture designs with two theoretical density classes were developed. The mixture composition for each class was constant and the only variable parameter was the type of the used lightweight aggregates-expanded glass (Liaver®), expanded clay (Liapor®), and foam glass (Ecoglas®). Accordingly, their pore characteristics and durability-related properties, such as sorptivity, open water porosity, and water penetration depth, were examined. To understand these phenomena, the permeable characteristic, tortuosity, was also calculated using a numerical approach incorporating X-ray micro-computed tomography. The examined results confirm that the durability characteristics of LWAC are strongly affected by the used aggregate types and are highly correlated with their pore structures. In terms of permeable characteristics, expanded glass is the most beneficial material among the used particles, and the systematic approach in this study can be used to examine the durability characteristic of LWAC.

Investigation of Mechanical Properties, Durability and Microstructure of Low-Clinker High-Performance Concretes Incorporating Ground Granulated Blast Furnace Slag, Siliceous Fly Ash and Silica Fume

The main assumption of eco-efficient High-Performance Concrete (HPC) design is the reduction of Portland cement clinker content without negatively affecting the composite’s mechanical and durability properties. In this paper, three low-clinker HPC mixtures incorporating slag cement (CEM III/B as per EN 197-1) and Supplementary Cementitious Materials (SCMs)—Ground Granulated Blast Furnace Slag (GGBFS), Siliceous Fly Ash (SFA) and Silica Fume (SF)—were designed. The maximum amount of Portland cement clinker from CEM III/B varied from 64 to 116 kg in 1 m3 of concrete mix. The compressive strength of HPC at 2, 7, 14, 28, 56, 90 days, and 2 years after casting, as well as the modulus of elasticity on 2-year-old specimens, was tested. The depth of water penetration under pressure and internal frost resistance in freeze–thaw tests were evaluated after 56 days of curing. Additionally, the concrete pH value tests were performed. The microstructure of 2-year-old HPC specimens was analyzed using Scanning Electron Microscopy (SEM). The research proved that it is possible to obtain low-clinker High-Performance Concretes that reach compressive strength of 76–92 MPa after 28 days of curing, show high values of modulus of elasticity (49–52 GPa) as well as increased resistance to frost and water penetration under pressure.

Durability and Mechanical Properties of Self-compacting Concretes with Combined Use of Aluminium Oxide Nanoparticles and Glass Fiber

The presence of fibers in concrete specimens has an effective role on how the specimens were failed. In this study, the effects of aluminium oxide nanoparticles on the workability, mechanical and, durability properties of SCCs containing glass fibers were investigated. Glass fibers contents of 0, 0.5, 1, and 1.5 % by volume of concrete and aluminium oxide nanoparticles contents of 0, 0.5, 1, 1.5, 2, and 3 % by weight of cement were used. The properties of fresh concrete were evaluated according to EFNARC consideartions. The mechanical properties were evaluated by compressive strength, splitting tensile strength, and ultrasonic pulse velocity tests. The durability of the specimens was also measured using water absorption tests, water penetration depth and, electrical resistivity. Combined use of 2% aluminium oxide nanoparticles and 1% glass fiber has increased the compressive and tensile strengths of SCCs by 59% and 119.2%, respectively. Aluminium nanoparticles have a very high specific surface area and their reactivity causes them to react rapidly with calcium hydroxide to produce silicate-hydrate gels. Therefore, calcium hydroxide crystals are reduced and the cavities in the cement gel are filled and the compressive strength is increased. The use of aluminium oxide nanoparticles along with glass fibers reduces the water absorption rate compared to the sample without these materials. This is one of the effective properties of aluminium oxide nanoparticles, which increases the resistance to adverse environmental factors by reducing water absorption.

Investigation of Silane Impregnation for Protection of Alkali‐Activated Slag Mortar

This paper investigated the effects of silane impregnation on the protective properties of alkali‐activated slag (AAS) mortars. The surface silane impregnation on water absorption, contact angle, and penetration depth were examined. The related protective mechanism regarding silane impregnation was analyzed by scanning electron microscope (SEM), X‐ray diffraction (XRD), and Fourier infrared spectroscopy (FT‐IR). The results showed that the surface of the AAS mortar after silane impregnation was transformed from hydrophilic to hydrophobic with an increased contact angle of 80° from 36° to 116°. And the water absorption was significantly decreased by 74.42% to 97.79%. The penetration depth of the two‐layer coating was dramatically higher than that of the one‐layer coating. The optimal coating method and dosage of silane were two‐layer coating and 200 g/m2. In addition, silane impregnation formed a stable Si‐O bond with AAS mortars through a hydrolytic condensation reaction and the −CH2CH3 group of the silane acted on the surface of the AAS mortars.

Influence of different surface treatment on water penetration resistance of concrete

Concrete is easily affected by all kinds of erosive substances during its use. Surface treatment is a simple method to improve the surface compactness and water permeability resistance of concrete. In this paper, silicate infiltration agent, nano-SiO2 and ethyl silicate are selected as concrete surface treatment material. The results of water permeability test showed that all the three treatments can effectively improve the water resistance. Silicate infiltration agent and nano-SiO2 were the most effective, which greatly reduced the penetration depth of water from 66 mm to 34mm and 32 mm, while ethyl silicate was reduced to 50 mm. Through the water permeability test curve, we can see that the water entered the concrete under a certain pressure, and the result showed the shape of high, middle and low edge.

Pirinç Kabuğu Atıklarının Köpük Beton Üretiminde Kullanılması

Günümüzde yapılan binaların büyük bölümünün temel yapıtaşını oluşturan betonun, dünyada sudan sonra en çok tüketilen yapı malzemesi olduğu belirtilmektedir. Betonun ana maddesi olan çimento, beton maliyeti içerisinde önemli paya sahip olmasından dolayı, çeşitli katkı maddelerinin çimento ikame maddesi olarak kullanımı çok sayıda araştırmaya konu olmaktadır. Ancak, kullanılan katkı maddelerinin beton özelliklerini ne düzeyde etkilediği öncelikli olarak belirlenmelidir. Bu çalışmada da pirinç (çeltik) kabuğu külünün çimento ikame maddesi olarak kullanımının bazı beton özelliklerini hangi düzeyde değiştirdiği belirlenmiştir. Çalışma kapsamında ayrıca pirinç kabuğunun ham halinin de beton içerisinde agrega olarak kullanılabilirliği değerlendirilmiş böylece, tarımsal atık olan pirinç kabuğunun bertaraf edilmesinde etkin bir yöntem de belirlenmeye çalışılmıştır. Çalışma sonuçları hem pirinç kabuğu külü hem de pirinç kabuğu agregası ilavesinin, betonun neredeyse bütün özelliklerini önemli ölçüde değiştirdiğini göstermektedir. Bu değişiklikler farklı özellikler açısından farklı düzeydedir. Çalışma sonucunda köpük miktarı arttıkça yayılma çapının da arttığı buna karşılık pirinç kabuğu ilavesinin yayılma çapını azalttığı belirlenmiştir. Pirinç kabuğu ilavesinin zamana bağlı su işleme derinliğini azalttığı, pirinç kabuğu ilavesi yüksek düzeyde olan numunelerin porozitesinin arttığı, basınç ve eğilme dayanımının ise azaldığı belirlenmiştir.

Water Penetration of Concrete made with Coarse Aggregates from Demolishing Waste

The results of laboratory investigations on water penetration in concrete made with coarse aggregates from demolishing waste are presented in this paper. Seven batches of standard size concrete cubes were cast with recycled aggregates from demolished concrete replacing coarse aggregates in percentages from 0% to 60%. The compressive strength of the samples was evaluated by non-destructive testing with the use of the Schimidz hammer. It was found that the strength reduces with an increase in recycled aggregate percentage. The maximum loss of strength due to the induction of recycled aggregates was 32% in the batch with 60%recycled aggregates. All samples were subject to constant water pressure of 5 bars for 72 hours. From the obtained results it was shown that the water penetration depth increases with increase in recycled aggregates rate. With 10% and 20% replacement the samples allowed less water to penetrate than conventional concrete samples, but 76% more penetration depth was recorded in samples with 60% replacement. Strength and water penetration results from dosages up to 20% show that the durability of the produced concrete allows it to be used in structural members with consideration of strength reduction in the design process. However, more water penetration with higher dosages of recycled aggregates needs proper care in design and usage of the concrete particularly for locations where concrete is exposed to water pressure.

Influence of in-situ casting temperature and curing regime on the properties of blended cement concretes under hot climatic conditions

Casting temperature and curing method significantly affect the properties of concrete, especially the blended cement concretes. Consequently, it is imperative to study the influence of casting temperature and curing regime on the properties of concretes. This paper reports results of a study conducted to evaluate the properties of plain and blended cement concretes prepared using very fine fly ash (VFFA), fly ash (FA), silica fume (SF), ground granulated blast furnace slag (GGBFS) and natural pozzolan (NP) cast and cured under varying temperature and curing conditions. The concrete specimens were prepared under natural summer atmosphere at intital concrete temperature of 25, 32, 38 or 45 °C. The specimens were cured under laboratory conditions by water ponding and under hot weaterher conditions by covering with wet burlap or applying a curing compound. The effect of casting temperature and curing regime on the properties of the studied concretes was evaluated by measuring compressive and split tensile strength up to 180 days, pulse velocity up to 90 days and depth of water penetration after 28 days of curing. As expected, the properties of concrete specimens cured by water ponding were better than those cured by covering with wet burlap or applying a curing compound. The properties of blended cement concretes were better than those of plain cement concretes at later ages due to the pozzolanic reaction. It is postulated that the optimum casting temperature is 32 °C for OPC and SF cement concretes while it is 38 °C for VFFA, FA, GGBFS and NP cement concretes. This finding differs with the current international practice of limiting the casting temperature to 35 °C.

Effect of Shrinkage Reducing Admixture on Drying Shrinkage of Concrete with Different w/c Ratios.

The reduction of the moisture content of concrete during the drying process reduces the concrete’s volume and causes it to shrink. In general, concrete shrinkage is a phenomenon that causes concrete volume to dwindle and can lead to durability problems. There are different types of this phenomenon, among them chemical shrinkage, autogenous shrinkage, drying shrinkage including free shrinkage and restrained shrinkage, and thermal contraction. Shrinkage-reducing admixtures are commercially available in different forms. The present study investigates the effect of liquid propylene glycol ether on mechanical properties and free shrinkage induced by drying at different water-cement (w/c) ratios. Furthermore, the effect of shrinkage-reducing admixtures on the properties of hardened concrete such as compressive and tensile strength, electrical resistivity, modulus of elasticity, free drying shrinkage, water absorption, and depth of water penetration was investigated. The results indicated that shrinkage reducing agents performed better in a low w/c ratio and resulted in up to 50% shrinkage reduction, which was due to the surface reduction of capillary pores. The prediction of free shrinkage due to drying was also performed using an artificial neural network.

Durability performance and dimensional stability of road concrete containing dry-shake surface hardener admixture

Durability and dimensional stability problems are emerged in road concrete due to traffic loads and environmental factors. The concrete surface treatment is one of the preferred methods to solve these problems economically. As it is known, surface treatment is applied to the concrete surface as dry-shaking and liquid. It is understood from the literature that there are very limited studies about the use of dry-shake hardener admixture in concrete mixtures. In the present study, the effect of dry-shake surface hardener admixture application on mechanical, durability and dimensional stability properties of concrete mixtures having different w/b ratios were investigated. Totally ten series of concrete mixtures coated with and without dry-shake surface hardener admixture were prepared for this purpose. The slump value of concrete mixtures was determined as 85 ± 5 mm. Vebe, slump and air content tests were performed for each mixture in fresh state and unit weights of mixtures were calculated. Also, compressive strength, modulus of elasticity, transport properties, abrasion resistance, freeze–thaw resistance and drying shrinkage behavior were investigated on the 7, 28 and 90-day specimens. In the light of the experiment results, compressive strength, modulus of elasticity, water sorptivity, abrasion resistance and drying shrinkage behavior of concrete mixtures were positively affected with adding of dry-shake surface hardener admixture. However, it was found that the dry-shake surface hardener admixture application had no significant effect on water absorption, depth of water penetration under pressure and freezing-thawing performances.

Use of marble slurry powder and fly ash to obtain sustainable concrete

Abstract Marble production is increasing with the increase in demand. Production of marble includes many steps from mining to finished product. While processing of marble stone, a huge quantity of waste generates in the various forms such as boulders, pebbles, grits, fines and slurry. In the absence of proper disposal plan, these wastes are dumped on forest land, roadsides etc. which results in deterioration of ecosystem of the nearby area. The marble slurry produced from the processing of marble has finer particle size which is airborne. It causes respiratory and eye infections to the human being. Also, fly ash is considered as waste byproduct generated from thermal power plants. The objective of this study was to investigate the feasibility of these industrial waste materials as replacement of conventional materials in concrete. In this study, 1 control mix and 4 mixes with replacements were prepared and investigated for workability, fresh density, flexural strength and DIN water permeability of prepared mixes. The result specifies that inclusion of fly ash as 35% cement replacement enhanced the fresh properties whereas admixture dosage was increased to get required workability in case of fine aggregate replacement by marble slurry powder (MSP). Fresh density increased on substitution of fine aggregate by marble slurry powder. The flexural strength was optimum for the control mix. The minimum water penetration depth was recorded for 20% fine aggregate replacement by marble slurry powder. The result indicated that the inclusion of marble slurry powder and fly ash may be used as partial substitution of fine aggregate and cement.