Papers by Keyword: Water Permeability

Abstract: This study explores the use of expanded polystyrene (EPS) waste as a sustainable additive to enhance the thermal and water resistance properties of ordinary Portland cement (OPC) paste. By dissolving EPS foam waste in acetone and toluene to create an EPS glue, various solvent ratios were tested to determine optimal formulations for improving cement properties. The results indicated that an acetone-to-toluene (A:T) ratio of 50:50 and an EPS-to-solvent (EPS:S) ratio of 1:1.5 provided the best balance of flowability, compressive strength, thermal conductivity, and water permeability. Specifically, a 5% replacement of OPC with EPS glue reduced thermal conductivity by approximately 36.8% and improved water penetration resistance by 38.8%, demonstrating that EPS glue is an effective and eco-friendly additive for cement. This research contributes to sustainable building practices by repurposing EPS waste and enhancing the performance of cement in construction applications.

Abstract: The main objective of this study is to reinforce the mechanical strength and water resistance abilities of sago starch biopolymer by incorporating ZnO nanofillers. The biopolymer based nanocomposite films were cast utilizing different weight percentages of ZnO nanofillers (0, 1, 3 or 5 wt%) in sago starch matrix through solution casting technique. Uniform dispersing of ZnO nanofillers throughout the sago starch matrix was achieved by sonication and also to prevent the formation of ZnO nanoparticles aggregates. This was to further reinforce the chemical barrier properties of the film The results illustrated that with the increase of loading of ZnO nanoparticles from 0 to 5 wt%, the tensile strength and elastic modulus improved from 0.180 to 0.980 MPa and from 3.410 to 6.401 MPa respectively for the films, attributing to the high surface to volume ratios, the high mechanical strength of ZnO nanoparticles and the strong nanofiller-matrix interfacial adhesion. The elongation at break also enhanced owing to the slippage of ZnO nanofillers and the oriented sago starch polymer which activated the shear flow of the sago starch polymer. Sago starch nanocomposites with ZnO loadings varied from 0 to 5 wt% demonstrated decreased water vapour permeability from 4.992 × 10⁻¹⁰ g m⁻¹ s⁻¹ Pa⁻¹ to 2.723 × 10⁻¹⁰ g m⁻¹ s⁻¹ Pa⁻¹.

Abstract: The paper presents investigation results for coatings obtained using thermal plasma treatment of wooden products. Such parameters of plasma treatment as temperatures at different distances from the surface, water absorption, and contact angles with water are measured in this paper.

Abstract: The study was to use Thai lignite fly ash and metakaolin to produce geopolymer paste as binder material in pervious concrete. The proper ratio of fly ash to metakaolin were varied as 100:0, 70:30, and 50:50. Alkali solution to pozzolan (L/P) ratios viz., 0.5, 0.6 and 0.8 by weight were prepared. The mechanical and characterization of pervious geopolymer concrete (PGC) were carried out. The results presented that the particle of fly ash was sphere with smooth surface, while metakaolin was partly agglomerated and irregular shaped. The increase of fly ash in the ratio of fly ash to metakaolin affected the lower requirement of volume of alkali solution. The compressive strength and of pervious geopolymer concrete at 28 days were 3.74-5.41. The void ratio and water permeability were 28.54-30.74% and 1.90-2.09 cm/sec, respectively. Therefore, geopolymer paste from fly ash and metakaolin could be used for pervious concrete with satisfied properties. However, the price of pervious cement concrete is 1,898-2,168 THB/m³, while the price of pervious geopolymer concrete is 2,123-4,173 THB/m³ due to the energy cost to transform kaolin into metakaolin by an electric furnace. The cost can be reduced by increasing the ratio of fly ash to metakaolin.

Abstract: The penetration of water and chloride ion into the concrete is of factors that cause rust and corrosion in rebars by reaching the existing reinforcement surface in reinforced concrete structures. In this study, effect of using Asphalt Plant Surplus Filler as a partial replacement of cement with replacement values of 0, 5, 10, 15 and 20% on permeability and electrical resistance of cement mortar were investigated with the aim of decreasing cement consumption. In order to determine the penetration of water, 10 cubic specimens with the size of 150 mm were made and tested. In order to determine chloride ion penetration, 20 cylindrical specimens with a length of 50 and a diameter of 100 mm were studied at the ages of 28 and 56 days. To test the electrical resistivity of cement mortar, 30 cubic specimens with the size of 100 mm were tested at the ages of 7, 28 and 56 days. According to the results of the experiments, adding filler to the cement mortar enhances the penetration of water and chloride ion. Electrical resistivity generally increases with the increase of specimen age. Furthermore, the filler increment indicates the reduction of electrical resistivity.

Abstract: Much of the existing water infrastructure across the world was constructed using masonry in the last 200 years and many of these structures were built with pre-Portland cement binders. Although these mortars exhibit good workability and high water retention in the plastic state, the water tightness deteriorates over the years resulting in a pressing need for suitable repair materials. The addition of polypropylene micorfibre in cement-based systems was found to be effective in reducing water permeability. But the effect of polymeric fibres on the permeability coefficient of hydraulic lime mortar (HLM) is unknown. Therefore, this paper focuses on measuring water permeability in fibre reinforced HLM. Besides, this study examined the application of nanolime onto the aforementioned mortars and its effect on their water permeability. Accordingly, a permeability cell was setup to monitor the onset of the steady state condition in fluid flow. Companion data was generated for the mechanical performance of these mortars. The results show that in hydraulic lime mortar, there is likely an optimal fibre dosage in order to reduce the permeability coefficient. Unlike with Portland cement mortar, this dosage is significantly lower. As well, applying nanolime was most beneficial in limiting water permeability in the natural hydraulic lime mortars.

Abstract: It’s quite often that dispensing a topping material like concrete crystalline penetration sealer materials onto the surface of a plastic substance such as concrete to extend its service life span by surface protections from outside breakthrough. When applied to concrete it reacts with calcium hydroxide and reduces the porosity and permeability of the concrete matrix. This serves to increase the hardness and chemical resistance which, in turn, increases the service life span of the surface. A series of tests, such as rapid chloride permeability test, scanning electron microscope, and mercury intrusion porosimetry, were performed on the concrete test samples to examine the durability, by taking the penetration depth of concrete crystalline penetration sealer materials as a characterization parameter describing the durability in relation to water resistance. The penetration depth is a critical property for concrete crystalline penetration sealer materials to function effectively. The deeper the penetration, the greater the thickness of concrete strengthened, thus improving wear resistance, the life span and durability. The desirable depth drawn from tests is about 10mm with a minimum of 5mm. However the regular attainment of such penetration will require considerable care in surface preparation and in assuring that the concrete is properly dry. The quality of the concrete will also be a major factor in the depth of penetration obtained. Penetration depths may be greater with poor quality porous concrete while a 10mm depth may not be possible with high-quality dense concrete. Other Factors affecting concrete sealer penetration depth are related to the process, such as coverage and application, a user who should understand how it works, and material itself, having its own image.

Abstract: Pseudo-ductile cementitious composites (PDCC) are a new type of special discontinuous random-fibers reinforced cementitious composites with high tensile ductility achieved by the uniform formation of multiple cracks along the length of the specimen. In the present study, rubber particle was introduced into the cementitious composites as the artificial flaw. The tensile properties, compressive strength, water permeability and shrinkage of PDCC with various volume contents and size of rubber particles were measured. The test results show that incorporation of rubber particle will reduce the compressive strength and first cracking strength of PDCC. With increased size and volume of rubber particles, the compressive strength is increased. To achieve maximum tensile ductility, optimum rubber content and size should be employed. Water permeability is found to be similar for various PDCC mixes with or without rubber addition. The content of rubber particle plays a significant role on the dry shrinkage of PDCC, while the particle size only has a slight effect.

Abstract: Nowadays, its more common of dispensing a topping material like concrete crystalline penetration sealer materials (CSM) onto the surface of a plastic substance such as concrete to extend its service life span by surface protections from outside breakthrough. Its known as the CSM may penetrate into the existing pores or possible cracks in such a way that it may form crystals to block the potential paths which provide breakthrough for any unknown materials. Even though all kinds of test data and researches have been reported to boast of its advantages in both theoretical technologies and application functions, to accept that as an agreed fact, namely the major components and those proportions have not been fully announced in public or research. This study employed various experiments, such as scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD), X-ray fluorescence (XRF) and Fourier transform infrared spectroscopy (FT-IR), to identify key components of CSM for developing another type of CSM so that its components could be open for the public. There are two types of commercial CSM adopted for the tests and then thru a series of discusses of test results the most possible components of CSM are proposed as a future reference of CSM related researches.

Abstract: Curing conditions is one of the most influential factors on mechanical properties and durability of concrete. The mechanical properties (strength and dynamic modulus of elasticity) and durability (water permeability, air permeability and coulomb electric flux) of concrete under water curing and air curing were analyzed through the tests, and the significance of the curing conditions influence on mechanical properties and durability were compared. Test results indicate that the effect of curing conditions on the durability was much large than on the mechanical properties, and strength should not be the single control indicator while considering the effect of curing, moreover the some durability indicators of concrete also should be taken into consideration, which can provide the reference for engineering application.