Investigation on physical and mechanical properties of manufactured sand concrete Haoyu Liao, Zongping Chen, Ji Zhou and Yuhan Liang
Abstract; Full Text (1730K) .	pages 177-188.	DOI: 10.12989/acc.2024.16.4.177

Abstract
In the context of the shortage of river sand, two types of manufactured sand (MS) were used to partially replace river sand (RS) to design manufactured sand concrete (MSC). A total of 81 specimens were designed for uniaxial compression test and beam flexure test. Two parameters were considered in the tests, including the types of MS (i.e. limestone manufactured sand (LMS), pebble manufactured sand (PMS)) and the MS replacement percentage (i.e., 0%, 25%, 50%, 75%, 100%). The stress-strain curves of MSC were obtained. The effects of these parameters on the compressive strength, elastic modulus, peak strain, toughness and flexural strength were discussed. Additionally, the sensitivity of particle size distributions to the performance of MSC was evaluated based on the grey correlation analysis. The results showed that compared with river sand concrete (RSC), the rising slope of the stress-strain curves of limestone manufactured sand concrete (LMSC) and pebble manufactured sand concrete (PMSC) were higher, the descending phrase of LMSC were gentle but that of PMSC showed an opposite trend. The physical and mechanical properties of MSC were affected by the MS replacement percentage except the compressive strength of PMSC. When the replacement percentage of LMS and PMS were 50% and 25% respectively, the corresponding performances of LMSC and PMSC were better. In generally, when the replacement percentage of LMS and PMS were same, the comprehensive performance of LMSC were better than that of PMSC. The constitutive model and the equations for mechanical properties were proposed. The influence of particle ranging from 0.15 mm to 0 mm on the performance of MSC was lower than particle ranging from 4.75 mm to 0.15 mm but this influence should not be ignored.

Key Words
limestone manufactured sand (LMS); manufactured sand concrete (MSC); mechanical properties; particle size distributions; pebble manufactured sand (PMS); stress-strain relationships

Address
(1) Haoyu Liao, Zongping Chen, Ji Zhou, Yuhan Liang:
College of Civil Engineering and Architecture, Guangxi University, 530004 Nanning, P.R. China;
(2) Zongping Chen:
College of Architecture and Civil Engineering, Nanning University, Nanning 530200, P.R. China;
(3) Zongping Chen:
Key Laboratory of Disaster Prevention and Structural Safety of Ministry of Education, Guangxi University, Nanning 530004, Guangxi, P.R. China

Bending and stability information of cylindrical structures in the application of sports equipment Xiaoyuan Liu, Radzliyana Radzuwan and Nadiah Diyana Tan Binti Abdullah
Abstract; Full Text (1469K) .	pages 189-203.	DOI: 10.12989/acc.2024.16.4.189

Abstract
This study investigates the bending and stability properties of cylindrical constructions, with a focus on their use in the design and implementation of sporting equipment. The work focuses on a cylindrical construction resembling nanomotors, similar to components seen in sports equipment, using mathematical modeling based on high-order beam theory and nonlocal strain gradient theory. The analysis provides important insights into the dynamic behavior of these systems, revealing light on the impact of numerous factors such as rotational velocity, section change rate, and structural dimensions. The results show a relationship between angular velocity growth and section change rate, which leads to an increase in fundamental frequency values. Furthermore, the research emphasizes the effect of structural factors on dynamic deflection, giving critical information for increasing the stability and performance of sporting equipment. This study adds to the area of sports engineering by providing a more nuanced understanding of how cylindrical constructions react under diverse settings. The results will help to guide the design and manufacturing processes of sports equipment, assuring improved stability and performance for players across a wide range of sports.

Key Words
bending characteristics; cylindrical structures; sports equipment design; stability analysis; structural dynamics

Address
(1) Xiaoyuan Liu:
Faculty of Physical education, Nanchang University, Nanchang 330031, Jiangxi, China;
(2) Xiaoyuan Liu, Radzliyana Radzuwan, Nadiah Diyana Tan Binti Abdullah:
Faculty of Sport Science and Recreation, Universiti Tekhnologi Mara, Kuala Lumpur 70300, Malaysia.

open access
Evaluation of Near Surface Mounted (NSM) FRP technique for strengthening of reinforced concrete slabs Chunwei Zhang and M. Abedini
Abstract; Full Text (2451K) .	pages 205-216.	DOI: 10.12989/acc.2024.16.4.205

Abstract
Concrete structures may become vulnerable during their lifetime due to several reasons such as degradation of their material properties; design or construction errors; and environmental damage due to earthquake. These structures should be repaired or strengthened to ensure proper performance for the current service load demands. Several methods have been investigated and applied for the strengthening of reinforced concrete (RC) structures using various materials. Fiber reinforced polymer (FRP) reinforcement is one of the most recent type of material for the strengthening purpose of RC structures. The main objective of the present research is to identify the behavior of reinforced concrete slabs strengthened with FRP bars by using near surface mounted (NSM) technique. Validation study is conducted based on the experimental test available in the literature to investigate the accuracy of finite element models using LS-DYNA to present the behavior of the models. A parametric analysis is conducted on the effect of FRP bar diameters, number of grooves, groove intervals as well as width and height of the grooves on the flexural behavior of strengthened reinforced slabs. Performance of strengthening RC slabs with NSM FRP bars was confirmed by comparing the results of strengthening reinforced slabs with control slab. The numerical results of mid-span deflection and stress time histories were reported. According to the numerical analysis results, the model with three grooves, FRP bar diameter of 10 mm and grooves distances of 100 mm is the most ideal and desirable model in this research. The results demonstrated that strengthening of reinforced concrete slabs using FRP by NSM method will have a significant effect on the performance of the slabs.

Key Words
fiber reinforced polymer; finite element model; near surface mounted technique; RC slab

Address
Multidisciplinary Center for Infrastructure Engineering, Shenyang University of Technology, Shenyang 110870, China.