RESUMEN
The purpose of this experimental paper is to examine the adhesion properties between non-woven plastic sheets and cement mortar. Specifically, the effect of w/c ratio and quantity of superplasticizer on the peeling force required for the detachment of tissue from the surface of prisms was studied in detail. Therefore, two types of mortar mixtures were prepared: (1) mixtures without superplasticizer with three different w/c ratios of 0.45, 0.50, and 0.55, and (2) mixtures with reduced amounts of water and three various percentages of superplasticizer of 0.0%, 1.11%, and 2.17% (by weight of cement). For this purpose, bond tests with a special setup, interferometry and microscopic analyses, and mechanical tests were performed. The results highlight that non-woven sheets had strong adhesion to cement mortar without using any adhesive materials. However, the peeling force improved by 15.78% as the w/c ratio increased from 0.50 to 0.55. Conversely, this force declined by 24.50% as the w/c ratio decreased from 0.50 to 0.45. In addition, the peeling force decreased by 20.62% as the w/c ratio decreased from 0.50 to 0.45 and 1.11% superplasticizer was added to the mixtures. This property decreased further by 38.29% as the w/c ratio lowered to 0.40, and the amount of superplasticizer increased to 2.17%. The interferometry and microscopic analyses clearly demonstrate that the adhesion between tissue and mortar is largely related to the surface texture, amount of cement paste, and quantity of residual fibers on the surfaces of samples. It indicates that mortar samples with higher w/c ratios had a smoother surface, and providing more contact area for microfilaments, which resulted in thicker layers of remaining fibers compared to the specimens with a lower w/c ratio. Even though there was not much difference in the surface texture of specimens with superplasticizer and lower w/c ratios, because of their similar workability. Still, thicker layers of microfilaments remained on the surface of specimens containing a lower amount of superplasticizer, which resulted in strong adhesion between sheet and cement mortar.
RESUMEN
This study will investigate the effect of non-woven PET plastic tissue on the fresh, physical, mechanical, acoustic, thermal, and microstructural behaviors of concrete. Including reference specimens, non-woven fabrics were considered in two ways: (a) as a layer with four various configurations of 1-layer, 2-sides, 3-sides, and full wrapping (4-sides) to strengthen specimens, and (b) as (10 × 10) mm cut pieces with three different incorporated percentages of 0.25%, 0.50%, and 0.75%. Based on the experimental results, mechanical properties (compressive, split tensile, and flexural strengths) were remarkably improved by applying non-woven sheets as a layer. For instance, the cylindrical compressive and split tensile strengths were improved by 13.40% and 15.12% for the strengthened specimens compared to the reference specimens, respectively. Moreover, control specimens were damaged to many fragments after mechanical testing, but the samples strengthened by such fabrics or containing cut pieces were maintained and not separated into many small parts. The acoustic behavior and thermal conductivity declined by 9.83% and 19.67% with the attachment of tissue on one side and 2-sides, respectively. Acoustic behaviors decreased by 10.0%, 17.60%, and 26.30% and thermal conductivity decreased by 6.60%, 12.10%, and 15.50%, with the incorporation of 0.25%, 0.50%, and 0.75% of cut pieces, respectively. Finally, it was discovered that non-woven tissue is advised to enhance particular properties of concrete.
RESUMEN
In this paper, supplementary cementitious materials are used as a substitute for cement to decrease carbon dioxide emissions. A by-product of the iron manufacturing industry, ground granulated blast-furnace slag (GGBS), known to improve some performance characteristics of concrete, is used as an effective cement replacement to manufacture mortar samples. Here, the influence of curing conditions on the durability of samples including various amounts of GGBS is investigated experimentally and numerically. Twelve high-strength Portland cement CEM I 52.5 N samples were prepared, in which 0%, 45%, 60%, and 80% of cement were substituted by GGBS. In addition, three curing conditions (standard, dry, and cold curing) were applied to the samples. Durability aspects were studied through porosity, permeability, and water absorption. Experimental results indicate that samples cured in standard conditions gave the best performance in comparison to other curing conditions. Furthermore, samples incorporating 45% of GGBS have superior durability properties. Permeability and water absorption were improved by 17% and 18%, respectively, compared to the reference sample. Thereafter, data from capillary suction experiments were used to numerically determine the hydraulic properties based on a Bayesian inversion approach, namely the Markov Chain Monte Carlo method. Finally, the developed numerical model accurately estimates the hydraulic characteristics of mortar samples and greatly matches the measured water inflow over time through the samples.
RESUMEN
It is a fact that plastic packages are widely used over the world. This large-scale consumption has resulted in a decrease of the initial resources used to manufacture the packages and has made it more of a challenge to dispose the increased amount of solid plastic wastes. Plastic waste is one of the most significant types of waste materials in the world, owing to its non-degradation and low biodegradability. The presence of large quantities of plastic waste has led to a number of environmental problems. Various researches have already been conducted to find a safe and environmentally friendly solution for the disposal of plastic wastes. Recently, different types of plastic have been incorporated into concrete mixtures because of its long service life and lower weight in order to eliminate or reduce environmental problems. This paper presents an overview of previously published research papers, which is investigating the use of different types of plastic wastes in concrete mixtures. In addition, a global view is summarized regarding the effects of plastic waste on fresh, mechanical, thermal, and acoustical properties of concrete.
