Publications
Shear and Flexural Strength of Pumice Lightweight Concrete Beams with Silica Fume
Oct 1, 2025Journal journal of Research on Engineering Structures and Materials
Publisher MIM Research Group
DOI http://dx.doi.org/10.17515/resm2025-971me0703rs
Recently, many types of research in Iraq have had the properties of lightweight concrete beams utilizing artificial and normal aggregate for economic reasons. Very limited works have been implemented to investigate the resistance of flexural and shear forces of structural lightweight aggregate concrete; therefore, it is important to study the properties and their structural behavior. The present work is to investigate the shear and flexural strength of lightweight concrete beams made of pumice with silica fume admixture. The lightweight concrete has been made by partial replacement of crushed gravel with 75% pumice and 7% silica fume. The value of compressive force strength is 29 MPa within twenty-eight days. A total of ten reinforced concrete beams is used, with dimensions of (150 x 150 x 750) mm, with and without silica fume, and with varying ratios of transverse reinforcement (stirrups). The deflection at mid-span was also measured using a mechanical dial gauge. Normal-weight concrete beams are also used to compare with the lightweight concrete beams. Beam behavior was assessed in terms of ultimate deflection, failure mode, and crack pattern. According to the experimental results, the prepared concrete's weight and strength met the LWC requirements. The results showed a significant effect of the transverse reinforcement ratio (stirrups), where the values of the shear and resistance of flexural rose when the amount of reinforcement increased. Furthermore, the appearance of the first crack has been significantly delayed as the reinforcement ratio rose.
Artificial Neural Network Model for Evaluating Load Capacity of RC Deep Beams
Apr 20, 2025Journal buildings
Publisher MDPI
DOI https://www.mdpi.com/2075-5309/15/8/1371
Issue 8
Volume 15
Using artificial neural networks (ANN), numerous models were developed for predicting the ultimate shear strength of reinforced concrete deep beams. Many experimental result databases from earlier research were carefully gathered for this study. Two hundred fifty-three findings from experiments were included in this database. The ultimate shear strength was the output parameter, while ten factors were determined as input parameters for the ANN model based on the completed literature research. The required model was constructed using a back propagation neural network. The model of the neural networks was determined using the trial-and-error method. It was discovered that, inside the range of the input boundaries considered, the ANN model could accurately estimate the ultimate shear strength of deep beams. The measured shear strength and the shear strength predicted by the ANN model have a high correlation coefficient of 0.97, indicating a strong relationship between the predicted and actual values. The results show that, given the range of input parameters, ANN offers an excellent agreement of interest as a practical technique for estimating the ultimate shear strength. A parametric investigation was performed using the trained neural network model to assess how the input parameters affected the shear strength capacity of deep beams.
The effect of real curing temperatures on early age concrete strength development in massive concrete structures
Jan 20, 2025Journal EUROPEAN JOURNAL OF ENVIRONMENTAL AND CIVIL ENGINEERING
Publisher Taylor and Francis Group
DOI https://doi.org/10.1080/19648189.2025.2458294
Issue 9
Volume 25
At the early maturity stage, the curing temperature has a significant impact on the mechanical properties of concrete. Concrete cubes are cured in water baths at different temperatures—5 C, 20 C, 35 C, and 50 �C—in order to measure their compressive strength. This method is predicated on the knowledge that the pace of cement hydration is strongly influenced by the curing temperature. Then, the realistic curing temperature regime was imposed where the temperature of the curing water was modified based on the temperature patterns obtained from semi-adiabatic testing of concrete mixes to simulate curing conditions in the core of massive concrete structures. Ordinary Concrete: Compared to specimens cured at an isothermal curing at 20 C, those cured in water baths at realistic curing showed an increase in compressive strength of 48% at seven days and 18.5% at 28 days. Fly Ash 18% Replacement: Compared to specimens cured at at 20 C, the compressive strength of those cured at realistic curing increased by 45% at seven days, with a modest rise of 0.2% by the 28th day. Slag 18% Replacement: Compared to specimens cured at 20 C, the compressive strength of those cured at realistic curing increased significantly by 121% at seven days and by 21.7% at 28 days.
Investigation the influence of nano ceramic on the mechanical properties and shrinkage of lightweight concrete containing silica fume
Jan 9, 2022Journal Materials Today: Proceedings
Publisher ELSEVIER
Volume 61
This study examined the influence of Nano waste ceramic on mechanical features and shrinkage of lightweight (unit of weight) concrete using pumice stone to substitute part of coarse aggregate with ratios (10, 30, 50, 70, and 90) %. (10) % silica fume used in all mixes. Waste ceramic power which milled to produce Nano waste ceramic as a pozzolan which used as additive by (0.5, 1, 2, 3, 4 and 5) % for the analysis of its influence on properties of such concrete. This weight was ranges from 1600 to 1800 kg/m3, and all samples tested in two ages (7 and 28) days. The results show that at (50) % replacing of pumice aggregate light weight concrete structure was obtained, and at using (2) % Nano waste ceramic the mechanical properties and shrinkage improves significantly. Copyright 2022 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Recent Advances in Mechanical Engineering and Nanomaterials
Numerical analysis of neck and bulge propagation in anisotropic tubes subject to axial loading and internal pressure
Jun 9, 2014Journal Finite Elements in Analysis and Design
Publisher ELSEVIER
Volume 90