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The disposal of ceramic tile waste poses a significant environmental challenge in the construction industry. This study aims to explore the influence of calcium carbonate (CC) on the properties of self-compacting concrete (SCC) incorporating porcelain tile waste as a coarse aggregate replacement. The objective is to enhance the performance of SCC while addressing the limitations of recycled ceramic aggregates and achieving the desired strength class. SCC specimens were cast by partially and completely substituting natural crushed rock with varying percentages of porcelain tile aggregates (PTA-0, 25 %, 50 %, 75 %, and 100 %) and cement with calcium carbonate (CC-10 %, 20 %, and 30 %). Workability assessments, mechanical properties, and durability were evaluated and compared against those of reference concrete. The experimental findings revealed that the incorporation of CC and PTA positively influenced the workability, mechanical properties and durability of SCC. Notably, the SCC mixture incorporating 10 %CC and 25 %PTA demonstrated exceptional performance, achieving the highest compressive strength of 64.9 MPa at 28 days. Moreover, even with complete substitution, the compressive strength reduction remained below 5 %. These results highlight the potential of PTA and CC-based SCC mixtures as an efficient and sustainable approach for utilizing porcelain tile waste in high performance concrete production. The findings contribute to addressing environmental concerns, promoting waste management practices, and reducing the reliance on natural resources in the construction industry.

In this work, the effects of recycled concrete aggregate, modified with mineral admixtures and nanosilica, on the mechanical properties and performance of concrete after curing in tap water for 28 and 90 days were investigated. The compressive (ƒc), indirect tensile (ƒt), and flexural (ƒb) strengths for the cured concrete specimens were measured, and the concrete strength ratios were analyzed. The water and rapid chloride permeabilities were measured. SEM analysis of the microstructure was also performed. The coarse aggregates used were dolomite (control) and recycled concrete aggregate, incorporating different mineral admixtures, including ground, granulated blast slag, granite, and nanosilica. It was found that the slump values of the dolomite concrete decreased compared with recycled aggregate concrete. Compared to the control mix produced with the recycled aggregate, the slump value of the concrete mixes created with the recycled aggregate increased by approximately 11.1% with the addition of binary cementing materials of 1% NS. The results also indicate that the concrete mix containing the recycled aggregate had the highest compressive strength, tensile strength, and flexural strength compared to that of the dolomite aggregate. Regarding the compressive strength, the addition of 1% NS and 15% slag improved the physico-mechanical properties of the recycled aggregate concretes compared to the other mixes after curing in tap water. Compared to the other mixes, the concrete mix containing 1% NS and 15% slag had a comparatively dense and compact microstructure. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering (17264073) is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study offers numerical simulation results using the ABAQUS/CAE version 2019 finite element computer application to examine the performance, and residual strength of eight recycle aggregate RC one-way slabs. Six strengthened by NSM CFRP plates were presented to study the impact of several parameters on their structural behavior. The experimental results of four selected slabs under monotonic load, plus one slab under repeated load, were validated numerically. Then the numerical analysis was extended to different parameters investigation, such as the impact of added CFRP length on ultimate load capacity and load-deflection response and the impact of concrete compressive strength value on the structural performance of slabs. This article aims to provide a numerical model for simulating the nonlinear behavior of such slabs, including a trustworthy finite element model approach and constitutive material models. In aspects of load-deflection and cracking patterns, comparisons between computational and experimental models are provided, and a reasonable fit is demonstrated. The average ratio of numerical model ultimate load and deflections to experimentally tested slabs were 0.992 and 0.913, respectively. As a result, finite element analysis may be regarded as a preferred and trustworthy approach for simulating the non-linear behavior of one-way slabs (strengthened or not) in terms of complexity, difficulty, time savings, human effort, and money.

In this work, the effects of recycled concrete aggregate, modified with mineral admixtures and nanosilica, on the mechanical properties and performance of concrete after curing in tap water for 28 and 90 days were investigated. The compressive (ƒc), indirect tensile (ƒt), and flexural (ƒb) strengths for the cured concrete specimens were measured, and the concrete strength ratios were analyzed. The water and rapid chloride permeabilities were measured. SEM analysis of the microstructure was also performed. The coarse aggregates used were dolomite (control) and recycled concrete aggregate, incorporating different mineral admixtures, including ground, granulated blast slag, granite, and nanosilica. It was found that the slump values of the dolomite concrete decreased compared with recycled aggregate concrete. Compared to the control mix produced with the recycled aggregate, the slump value of the concrete mixes created with the recycled aggregate increased by approximately 11.1% with the addition of binary cementing materials of 1% NS. The results also indicate that the concrete mix containing the recycled aggregate had the highest compressive strength, tensile strength, and flexural strength compared to that of the dolomite aggregate. Regarding the compressive strength, the addition of 1% NS and 15% slag improved the physico-mechanical properties of the recycled aggregate concretes compared to the other mixes after curing in tap water. Compared to the other mixes, the concrete mix containing 1% NS and 15% slag had a comparatively dense and compact microstructure.

Recycled aggregates (RA) are obtained from construction and demolished waste, laboratory crushed concrete and concrete waste at RMC plants. The concrete made from recycled aggregate is known as recycled aggregate concrete. The use of recycled aggregate is very beneficial to the environment in civil works. Its usage also helps in financial saving as the cost of transportation and production energy cost of natural coarse aggregate (NCA) is reduced. In India, the recycled aggregate application in lower grade concrete work is observed. However, the effect of recycled aggregate on the strength and durability of concrete restricts its use in higher-grade work. This paper presents a series of tests carried out on recycled coarse aggregate (RCA) and recycled coarse aggregate concrete (RCAC) and test results are compared with the NCA and parent concrete made from NCA. Tests were carried out as per IS code and concrete was prepared using a two-stage mixing approach in the concrete mix design. M30 concrete mix of four RCAC samples was tested at 28 days of curing and in comparison with parent concrete, it is found that on an average compressive strength is decreased by 12.89% at 28 days curing. Adhered mortar increases the porosity of the recycled aggregate and forms a weak zone between aggregate surface and mortar. In addition, test results showed the defects in recycled aggregate and helped to identify the area where concentration is necessary to improve the quality of recycled aggregate using six sigma DMAIC methodology. Total of 12 defects were found in the process and raw material. Statistical analysis was used to evaluate the performance of all the mix made with RCA.

Huge volume of recycled aggregates are produced annually, in the economic and environmental view, they need to consume in the appropriate section of the construction industry. In this paper, a recycled aggregate has been used for seismic modeling of embankment-subsoil. The nonlinear software was employed in the modeling. For assessment modulus elasticity and lateral displacement of the model, the mechanical properties of the soil and the recycle aggregates designing have been selected as parameters. Three models, with the same geometry and different type of materials, have been configured. Results revealed the recycle aggregate enhances seismic mitigation of the model. The outcome of this study demonstrated using recycled aggregate in the construction industry impacts on (i) control strain and stress directions, (ii) minimize lateral displacement of the model, (iii) enhance modulus elasticity of the embankment-subsoil model, and (iv) the seismic stability of the embankment-subsoil model. The statistical analysis showed, the high accuracy for interpreting modulus elasticity of the model, and it is good evidence for numerical analysis accuracy results.

Copyright of New Building Materials / Xinxing Jianzhu Cailiao is the property of New Building Materials Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The present research intended to determine thermal properties (thermalconductivity, thermal diffusivity and specific heat) of concrete manufactured by recycle waste of clay brick and thermostone for using it as aggregate after crushing process. For this purpose, three concrete mixes were prepared one of them using crushed clay brick as aggregate and two others were used crushed thermostone as aggregate too, these three mixes compared with reference normal concrete mix.Specific heat was measured by using semi-adiabatic calorimeter method whereas thermal diffusivity was measured by using heating-cooling system. Thermal conductivity was obtained by multiplying the thermal diffusivity, specific heat and density. From experimental laboratory work, it was concluded that the thermal diffusivity increase with concrete density increment, but the specific heat was decreased with concrete density increment. Thermal conductivity had a linear relationship with thermal diffusivity. Mixing ratio also had an influence on thermal properties of concrete.