Water Permeability Of Concrete Research Articles

Electrical Indication of Modified Concrete´s and Mortar´s Ability Resist Chloride Ion Penetration

This article describes the ability of concrete and mortar mixtures with different fly ash contents to resist chloride ion penetration 14 and 28 days after casting. The Rapid Chloride Permeability Test (RCPT) in accordance to the norm ASTM C1202 was used in order to obtain qualitative indications of the chloride ion penetrability depending on the electrical conductance of concrete respectively mortar samples. Furthermore, the Automatic Concrete Water Permeability Apparatus at Four Cells C430X from Matest was used to measure the water permeability 28 days after casting. Finally, the uniaxial compressive strength was measured 28 days after casting. The following conclusions can be made. The results of the Chloride Permeability Test (RCPT) did not show a clear correlation between the ash content, the a/c ratio and the Chloride Ion Penetrability. However, the chloride diffusion coefficient for the hormone and mortar at 28 days tends to increase with increasing a / c ratio and decreases with the age of hydration. As for permeability, an increase in the permeability was found at 28 days of age with an increasing ratio of a/c ratio.

Assessment of Mechanical and Durability Properties of Concrete Containing PET Waste

Plastic waste is a silent threat to the environment, and their disposal is a serious issue. To sort out this issue, many efforts were made to reuse the plastic waste, but no significant results were achieved. On the contrary, concrete being the widely used construction material is facing problem due to unavailability of ingredient material (sand and coarse aggregate). In this study PET (polyethylene terephthalate) aggregates manufactured from the waste un-washed PET bottles in shredded form were used to partially replace fine aggregate and coarse aggregate in concrete in various percentages (0%, 5%, 10%, 15% and 20%). Various tests like workability, compressive strength, flexural strength, water permeability, abrasion resistance, dynamic and static modulus of elasticity were performed. The micro-structural analysis of the specimens was carried out using an optical microscope. It was found that the workability, compressive strength, flexural strength, dynamic and static modulus of elasticity decreased with the increasing amount of PET waste in concrete. Water permeability of concrete was found to increase with increasing amount of PET waste. In both the cases, i.e., when fine and coarse aggregates were replaced with PET waste, an improvement in the abrasion resistance of concrete was found.

Comparative Study on Water Permeability of Concrete Using Cylindrical Chamber Method and British Standard and Its Relation with Compressive Strength

Since the penetration of fluids (water, oil and chemicals) into concrete, plays a major role in the durability of concrete, this paper describes the effect of compressive strength of concrete on its permeability. Having revised the existing methods developed so far, the results of investigations into the permeability of different mixtures of concrete are presented. The results of the new method (cylindrical chamber method) used for the estimation of the permeability of 5 different strength grades concrete samples after different curing periods were compared with the comparative results obtained using British standard method (BS EN 12390-8:2009). These experiments tend to indicate a very good correlation between the two sets of results. Based on the test results, higher water/cement ratio and shorter curing period result in decreased compressive strength and increased permeability. The correlations between compressive strength and permeability parameters (penetration depth, average penetration flow velocity, permeability coefficient and penetration volume) are also investigated using a regression approach. It is concluded that power and second-order polynomial approximations can predict these correlations with a desirable accuracy.

Use of Two-Pressure-Head Method to Assess Water Permeability of Structural Concrete

Determining the water permeability of concrete in structures remains a conundrum because of difficulties in removing the influences of moisture. This study describes the extended flow-net theory developed on the basis of the two-pressure-head concept, which provides a means of measuring permeability under the partially saturated condition. Surface-mounted tests and standard laboratory water penetration tests were carried out to verify this approach. Before determining the water permeability, steady-state flow rates at two different pressure levels were evaluated and the effects of initial moisture conditions on flow behavior were investigated. The results indicate that the proposed approach does offer a useful means of determining the water permeability of structural concrete, although it cannot be claimed to be universally applicable for all moisture conditions likely to be encountered in practice.

The use of ultrasonic pulse velocity to estimate the water permeability of concretes

In this work we investigated the possibility of estimating the water permeability of concrete from the ultrasonic surface wave velocity (Rayleigh's waves). This is a method for the non-destructive permeability diagnosis of the in situ auscultation of a structure. Four ordinary concrete compositions with different W/C ratios and two self compacting concretes SCC were used. This study showed a decrease in of ultrasonic pulse velocity with the increase in the W/C ratio, this is due to the increase in porosity. Curing in air of the concrete specimens produces greater permeability than curing in water. The increase in the permeability with the increase of W/C ratio is more important for curing in water than for the curing in air. SCC1 has a lower permeability than that of SCC2, this difference is respectively 20% and 10 % for curing in air and in water. The study show that permeability estimation with ultrasonic surface waves is more reliable for curing in water mode than tin curing in air. The correlations obtained between the permeability and the indirect ultrasonic velocity are linear, with an inversely proportional relation.

The use of ultrasonic pulse velocity to estimate the water permeability of concretes

In this work we investigated the possibility of estimating the water permeability of concrete from the ultrasonic surface wave velocity (Rayleigh's waves). This is a method for the non-destructive permeability diagnosis of the in situ auscultation of a structure. Four ordinary concrete compositions with different W/C ratios and two self compacting concretes SCC were used. This study showed a decrease in of ultrasonic pulse velocity with the increase in the W/C ratio, this is due to the increase in porosity. Curing in air of the concrete specimens produces greater permeability than curing in water. The increase in the permeability with the increase of W/C ratio is more important for curing in water than for the curing in air. SCC1 has a lower permeability than that of SCC2, this difference is respectively 20% and 10 % for curing in air and in water. The study show that permeability estimation with ultrasonic surface waves is more reliable for curing in water mode than tin curing in air. The correlations obtained between the permeability and the indirect ultrasonic velocity are linear, with an inversely proportional relation.

Quantitative analysis of macro steel fiber influence on crack geometry and water permeability of concrete

In this work, the water permeability of the cracked concrete has been investigated. Three types of cylindrical specimens with different fiber content were pre-cracked by the feedback controlled splitting test, and the specimens without any fiber reinforcement were also studied as reference. The water permeability of the specimens with different crack width was measured by hydraulic permeability test. The coordinate data of the crack surface was collected by the self designed data acquisition system, the total crack length and surface area of the samples were analyzed, the crack geometry (tortuosity and roughness) was evaluated quantitatively. A modified factor ξ was introduced to the Poiseuille law to verify the permeability of the cracked specimen. The results showed that with the addition of macro steel fibers, the deformability of the specimens was improved significantly and the crack width could be controlled. The coefficient of the water permeability of the specimens was declined by fiber addition, the modified Poiseuille law could be used to evaluate the water permeability of the cracked concrete, the modified factor ξ decreased with the increasing of fiber dosage. The crack tortuosity and surface roughness increased obviously with the addition of steel fiber.

Comparison between the permeability water and gas permeability of the concretes under the effect of temperature

Characterization of permeability is essential to fully describe the transport phenomena occurring in porous medium at elevated temperatures. The aim of this work is to study the evolution of the inherent gas and water permeability of concretes with temperature variations. The tests were performed on two types of concretes (ordinary and pozzolanic) using Algerian local products. Addition of natural pozzolan, promoting use of local products, with a rate of 15% was incorporated in the pozzolanic concretes and samples (11x22cm) were subjected to different temperatures (200 °C, 300° C, 400° C, 600° C and 700° C). After cooling, gas and water permeability using, respectively, CEMBUREAU and CONTROLAB permeability devices were measured and loss of mass and compressive strength were then conducted. Experimental results of permeability and mechanical strength variations are shown and pozzolanic concretes depicted better characteristics both in terms of gas and water permeability as well as compressive strength in comparison with ordinary concrete.

New experimental method for evaluating the water permeability of concrete by a lateral flow procedure on a hollow cylindrical test piece

The durability of concrete depends to a large extent on the difficulty of external aggressive agents in penetrating the porous network of concrete. The ability of this material to withstand the intrusion of these aggressive agents is mainly characterized by permeability. The latter is influenced by the interconnected capillary pores which depend on the water/cement ratio (W/C).The objective of this study is: first, to review and discuss the main existing methods used to measure the water permeability of cementitious materials. Secondly, to propose a new experimental method which provides an increase in the area of contact of the water with the sample. The hollow cylindrical shape of the sample thus permits a transverse flow of the liquid from the inside to the outside. This method provides a high volumetric flow of water and ensures a good seal between the sample and the cell of the apparatus. The accuracy is much higher and the measurements are more representative. In order to validate the proposed experimental procedure, the study comprises 12 types of concrete with variable W/C ratio. The latter constitutes a means for characterizing the porous structure and the transfer properties in concrete.The results obtained show that the proposed method treats the disadvantages commonly encountered in current permeability apparatus. These results are reliable and explain the considerable influence of the W/C ratio on the water permeability of concrete.

Water Permeability Characteristics of Normal Strength Concrete Made from Crushed Clay Bricks as Coarse Aggregate

Water permeability characteristic of concrete made from crushed clay bricks as coarse aggregate is investigated and compared with concrete made from natural stone aggregate. For this, six different brick and five different natural stone samples were selected. Crushing strength of brick samples and water absorption of aggregate produced from them were also measured. Concrete samples of three different compressive strengths were prepared as per ACI mix design method from each of these aggregate samples. Compressive strength of concrete that could be achieved with brick aggregate varied between 19 and 28 MPa, whereas, for stone aggregate, compressive strength varied between 24 and 46 MPa. These samples were then tested for water permeability using the AT 315 machine as per EN 12390-8: “Depth of Penetration of Water under Pressure.” Experimental results and subsequent analysis indicate that water permeability of brick aggregate concrete is 225% to 550% higher than that of concrete made from natural stone aggregate of identical compressive strength. Water permeability was found to be directly related to compressive strength, water absorption, and porosity of hardened concrete. It was also observed that water permeability of concrete is influenced by water absorption of brick aggregate and crushing strength of brick.

Utilizing waste materials to enhance mechanical and durability characteristics of concrete incorporated with silica fume

Construction and demolition wastes are increasing significantly due to augmented boom of modern construction. Although the partial cement replacement materials do promote the idea of sustainable construction, the use of construction and demolition waste can also be considered to be viable option to advance the sustainability in modern construction practices. This paper investigates the use of industrial waste materials namely marble dust and crushed bricks as replacement of natural fine aggregates along with the use of silica fume as a partial cement replacement on the mechanical properties and durability characteristics of concrete. Partial replacement levels of waste materials were 10 and 20 percent by volume while the partial replacement level of silica fume was kept to 20 percent at all concrete samples. The results reported in this paper show that the use of marble dust as a replacement material to the natural fine aggregates resulted in an increase in the mechanical properties of concrete. However, the use of crushed bricks did not substantially contribute in the development of strength. Water permeability of concrete incorporated with both silica fume and waste materials (marble dust and crushed bricks) decreased significantly. The decrease in water permeability of concrete was attributed to the pozzolanic reaction of silica fume with calcium hydroxide of cement and the filler effect of the waste materials of marble dust and crushed bricks. The use of waste materials also enhance the freeze and thaw resistance of concrete. Authors strongly suggest that the pozzolanic reaction and the development of the microstructure of the concrete through the use of waste materials are largely responsible from the advances in the durability of concrete.

To Study the Durability Aspects of Concrete using Basalt Aggregate

Objective: To analyze and study the durability aspects of concrete using Basalt Aggregate with that of convention concrete. Methods: The cubes were being tested for four kinds of test to clarify the modulation of compressive strength, flexural strength, fire resistance and water permeability of concrete by using basalt as aggregate as per the mix design. The tests were carried out with 50%, 30% basalt as aggregate. Comparative analysis between concrete with normal aggregate and concrete with basalt aggregate was performed for durability aspects. Findings: The results showed considerable increase in compressive strength, flexural strength, fire resistance value and water permeability value with 50% and 30% basalt as aggregate. The study suggests that basalt aggregate is better in terms of mechanical properties and more economical alternative for aggregate in terms of durability as compared to normal aggregate. Improvement: The use of basalt as aggregate in concrete is a new practice and though not much work has already been done in this field, it is a field with much potential. The intent of this project has been fulfilled with significant improvement of concrete properties in compression, tension and flexure.

GWT – New Testing System for “in-situ” Measurements of Concrete Water Permeability

The paper presents principle of a German's Water permeation Test (GWT) and results of experimental study which was carried out to assess a possibility to implement in engineering practice a new testing system (GWT) for assessment of water permeability of concrete with the respect to a new European Standard (EN 12390-8). The testing details and procedure of evaluation of the results obtained by means of GWT have been also described.Research program consisted of laboratory tests and “in-situ” examinations of three concrete bridges situated along the national road nr 3 in Lower Silesia, Poland, close to Wrocław. Two types of concrete have been considered. Examinations carried out have shown that the results of standard water permeability measurements are with the agreement of “in-situ” NDT tests performed by means of GWT system. Obtained results confirmed that this new method is very useful for engineering practice. The “average flux of water” (qm) has been proposed as an evaluation parameter. It has been shown that concrete can be considered as water permeable if qm ≤ 0.32μm/sek.

An experimental and numerical study on water permeability of concrete

Durability of concrete depends largely on its water permeability, which is dominated by the composition and difficultly evaluated. This paper presents a three-dimensional (3D) FE algorithm to investigate the water transport performance in concrete. This FE model possesses three-phase mesostructure consisting of coarse aggregates, mortar matrix, and the interfacial transition zone (ITZ) which is practically modeled by the zero-thickness interface element. A series of numerical tests with regard to concrete samples containing different volume fractions of coarse aggregates are conducted. The calculated permeability coefficients are in reasonable accordance with the physical experiment data. Effects of aggregates and ITZ on the concrete permeability are also quantitatively studied by the numerical test. It is proved that the proposed algorithm is capable of modeling the permeable characteristics of concrete which is affected greatly by its heterogeneous mesostructure.

Effect of cattle manure ash on strength, workability and water permeability of concrete

Combustion is an attractive method for cattle manure waste disposal since it produces heat and electrical energy and minimizes groundwater and air pollution by consumption of the waste. A major problem arising from the combustion of cattle manure waste is the significant resultant quantity of cattle manure ash (CMA). In this paper, we study the strength, workability and water permeability of concrete when CMA is used as a partial replacement in cement. Three types of CMA were tested, namely CMA, CMA-M and CMA-U, which were generated after combustion at 200°C, 500°C and 800°C. The strength of concrete that contained CMA was determined using cubic samples (100mm edge) at 7, 28 and 56days. The workability was measured from the slump when the concrete was mixed manually or mechanically. The water permeability, including percentage, velocity and coefficient of water absorption of concrete, was determined at 7, 28 and 90days using an improved initial surface absorption test. The workability increased from CMA to CMA-M to CMA-U. The compressive strength increased with increasing particle size from CMA to CMA-M but decreased from CMA-M to CMA-U. The water permeability, including percentage, velocity and coefficient, increased from CMA to CMA-M to CMA-U at 7 and 28days. At 90days, the water permeability, including percentage, velocity and coefficient of water absorption of CMA-M concrete, were the lowest in the three CMA concretes. CMA-M was the best material in terms of its overall workability, strength and water permeability. Mechanical concrete mixing and vibration was the optimal preparation procedure. CMA can therefore be blended with cement for concrete production depending on the ultimate use.

Gas and water permeability of concrete

Abstract Concrete is used as a barrier on surface or near-surface facilities for the final disposal of low- and intermediate-level radioactive waste, where gas can be generated and affect the hydraulic properties and the processes taking place in concrete. In this framework, gas-transport properties of concrete samples were investigated using two different laboratory test set-ups: a non-steady-state equipment working under low injection pressures; and a newly fine-tuned steady-state set-up working under different pressures. Permeability decreased with water content increase but was also greatly affected by the hydraulic history of concrete (i.e. if it had been previously dried or wetted). The intrinsic permeability determined with gas flow was about two orders of magnitude higher than that determined with liquid water (10 −16 v. 10 −18 m 2 ), probably due to the chemical reactions taking place during saturation (carbonation). The relative gas permeability of concrete increased sharply for water degrees of saturation smaller than 50%. The boundary conditions also affected the gas permeability, which seemed to be mostly conditioned by the back pressure and the confining pressure, on the whole decreasing as the effective pressure increased. It is considered that the Klinkenberg effect was not relevant in the range of pressures applied.

The Effect of Green Inhibitor on strength and water permeability of concrete

Reinforce concrete durability treated with green inhibitor were experimentally studied. The permeability and strength of a concrete plays a critical and significant role in controlling the properties of concrete, and serviceability of reinforced concrete. It is a usual practice to assess the water permeability characteristics when assessing the durability characteristics. In the present investigation, initial surface absorption test was used to determine the water permeability of concrete of w/c (0.45) to simulate compacted and porous concrete. Bambusa arundinacea green inhibitor absorptions for 10min, 30min, 1h and 2h, is generally less than 0.25, 0.17, 0.1 and 0.07 ml/m2.s respectively, that is, the set ISAT standard for low permeability concrete. This might be possible as a result of residual alkalinity of potassium hydroxide (KOH) present in the concrete evident from inductively coupled plasma-mass spectrometry (ICPMS) result. KOH is adequate for passivation and reduction of permeability, which serve as a chemical water barriers or hydrophobic agents.Keywords: Concrete; Calcium-Silicate-Hydrate (C-S-H); Compressive strength; Permeability; Portlandite

The Effect of Green Inhibitor on strength and water permeability of concrete

Reinforce concrete durability treated with green inhibitor were experimentally studied. The permeability and strength of a concrete plays a critical and significant role in controlling the properties of concrete, and serviceability of reinforced concrete. It is a usual practice to assess the water permeability characteristics when assessing the durability characteristics. In the present investigation, initial surface absorption test was used to determine the water permeability of concrete of w/c (0.45) to simulate compacted and porous concrete. Bambusa arundinacea green inhibitor absorptions for 10min, 30min, 1h and 2h, is generally less than 0.25, 0.17, 0.1 and 0.07 ml/m2.s respectively, that is, the set ISAT standard for low permeability concrete. This might be possible as a result of residual alkalinity of potassium hydroxide (KOH) present in the concrete evident from inductively coupled plasma-mass spectrometry (ICPMS) result. KOH is adequate for passivation and reduction of permeability, which serve as a chemical water barriers or hydrophobic agents. Keywords : Concrete; Calcium-Silicate-Hydrate (C-S-H); Compressive strength; Permeability; Portlandite

Mechanical Properties of Water-Permeable Concrete Using Coated Recycled Aggregates and Material for Performance Improvement

The mechanical properties of water-permeable concrete after mixing with coated recycled aggregates, silica fume, and PVA fiber were investigated in this study. Recycled aggregate was coated double-layer and then mixed as the coarse aggregate of water-permeable concrete. As a result, the void ratio, water-permeability coefficient and strength decreased, as compared to concrete with mixed crushed aggregates. When both silica fume and PVA fiber was added, the strength of the water-permeable concrete increased (compressive strength : by 4.3%, flexural strength : by 2.1 times). Also, the freeze and thaw resistance of the water-permeable concrete increased by approximately 44.15% compared to the plain concrete with no added reinforcing element.

Physical Properties of Waste Concrete Recycled Aggregates According to Coating Factor

The physical properties of waste concrete recycled aggregate according to the mixing ratio of the coating agent and the number of coatings investigated in this study. As the result, the Density of recycled aggregate increased, as the mixing ratio of the coating agent and the number of coatings increased. The percent of water absorption decreased rapidly for all coating conditions, and potential contamination test showed that among 21 items of concern, five were detected. The compressive strength of the water-permeable concrete increased by approximately 16.2% as produced with coated recycled aggregate.