Boonchai Stitmannaithum

• D.Eng (Civil Engineering), University of Tokyo, Japan
• Professor at Chulalongkorn University

Capacity building for campus sustainability has been recognized as a process of strengthening the university stakeholders’ skills to minimize the negative impacts of current crises and emerging challenges. While many universities emphasize capacity building through research and education activities, most, if not all, neglect activities for non-acad...

A new approach that combines analytical two-parameter kinematic theory (2PKT) with machine learning (ML) models for estimating the shear capacity of embedded through-section (ETS)-strengthened reinforced concrete (RC) beams is proposed. The 2PKT was first developed to validate its representativeness and confidence against the available experimental...

This study evaluates the dynamic characteristics of an abandoned reinforced concrete building with structural deterioration and defects in its precast and cast in‐situ walls. Using ambient vibration and forced excitation, the dynamic characteristics (i.e., modal frequency, modal damping, and strain patterns) were extracted to evaluate existing perf...

Steel reinforcement is an essential part of reinforced concrete, providing structural strength. In case of fire, the steel reinforcement severely loses its mechanical properties, leading to structural collapse in some elevated temperatures. Thus, this work mainly investigates the mechanical properties of spliced and non-spliced steel reinforcements...

The structural performance of reinforced concrete (RC) beams strengthened in shear with embedded through-section (ETS) glass fiber-reinforced polymer (GFRP) bars is experimentally and analytically investigated. Three-point bending tests are performed. The investigated parameters include the number of existing steel stirrups (ρsw = 0.28%), concrete...

This study analytically and numerically investigated the shear performance of rectangular concrete beams strengthened with embedded through-section (ETS) glass fiber-reinforced polymer (GFRP) bars. The key features of the bonding-based approach were first formulated and then validated by comparing their mechanism with the actual shear resistance me...

In this study, the bond behaviour between the embedded through-section fibre-reinforced polymer (ETS FRP) bars and concrete is investigated using nonlinear finite element (FE) analysis. The pull-out scheme for the investigation of the interfacial interaction of ETS FRP bars adhesively bonded to concrete is presented. The proposed numerical study al...

Utilization of recycled glass as fine and coarse aggregates in concrete materials can give significant economical and environmental benefits, especially in the case of developing countries. However, alkali-silica reaction (ASR) will be a serious problem when the recycled glass is used as concrete aggregates. This paper shows an investigation of the...

The finite element (FE) method is a common and convenient tool for simulating the behaviors of reinforced concrete (RC) beams. However, the applicability of the FE method for simulating the structural responses of degraded RC beams repaired with steel fiber-reinforced concrete (SFRC) remains unclear. In this study, RC beams subjected to corrosion a...

This paper introduces a novel and simple model for estimation of the shear contribution of the fiber-reinforced polymer (FRP) strengthening system in the FRP-strengthened beams. The model utilizes the bonding-based approach, which considers the shear resisting mechanism of FRP-strengthened beam via the bond behavior between FRP strengthening system...

This paper presents an experimental investigation on reinforced concrete (RC) beams strengthened in shear with embedded through-section (ETS) steel and fiber reinforced polymer (FRP) bars anchored with and without a mechanical anchorage system. The responses of the beams, including the load–deflection relationship, crack patterns, modes of failure,...

This paper presents an experimental and numerical investigation on concrete members strengthened by embedded through-section (ETS) steel and glass fiber-reinforced polymer (GFRP) bars attached preferably with mechanical anchorage at the tension ends. The pullout tests to analyze the bond performance between ETS bars and concrete under various influ...

This study investigates the bond behavior between embedded through-section (ETS) fiber-reinforced polymer (FRP) bars and concrete, as well as its effect on the structural performance of beams strengthened in shear with ETS bars, through experiments, analytical evaluations, and numerical simulations. A series of pullout tests was carried out to anal...

This paper presents an experimental investigation of reinforced concrete beams strengthened in shear by embedded through-section (ETS) steel and glass fiber-reinforced polymer (GFRP) bars anchored preferably with mechanical anchorage at tension ends. The overall responses of the tested beams such as load-deflection relationships, crack patterns and...

In this paper, the performances of reinforced concrete (RC) beams strengthened in shear with steel fiber-reinforced concrete (SFRC) panels are investigated through experiment, analytical computation, and numerical analysis. An experimental program of RC beams strengthened by using SFRC panels, which were attached to both sides of the beams, is carr...

This paper presents a numerical investigation of the mechanical performance and ductility of concrete beams reinforced by both fiber-reinforced polymer (FRP) and steel tension reinforcement. Three-dimensional (3D) finite element (FE) analysis of beams with both FRP and steel reinforcement was conducted by first using ANSYS to verify the reliability...

To enhance the longevity of the reinforced concrete (RC) structures, different techniques have been used with success in the strengthening field and rehabilitation projects. Embedded through section (ETS) method uses an adhesive to bond fiber-reinforced polymer (FRP) or steel bars embedded through pre-drilled holes into the core of the concrete mem...

The embedded through-section (ETS) method has been used as a new technique to strengthen the reinforced concrete beams in shear. In this technique, the fiber-reinforced polymer (FRP) or steel rods are embedded through previously drilled holes into the concrete core. Most of the previous research concluded that the ETS method was proved to be partic...

Chulalongkorn University (CU) is located at the heart of Bangkok, which is one of the most traffic congested cities in the world. It is very crucial for the university to develop a green and clean transportation system that is good for both the CU community and the whole society. To reduce on-campus traffic, the university provides four parking bui...

The embedded-through section (ETS) method overcomes the main disadvantages of the two common shear strengthening techniques, externally bonding (EB) and near surface mounting (NSM), and most of previous researches indicated the improvements in the shear performance of the ETS technique in the comparison with the EB and NSM methods. The current stud...

Fiber reinforced polymer (FRP) bars have been recently used to reinforce concrete members in flexure due to their high tensile strength and especially in corrosive environments to improve the durability of concrete structures. However, FRPs have a low modulus of elasticity and a linear elastic behavior up to rupture, thus reinforced concrete (RC) c...

A method for estimating mix proportion of hardened OPC concrete is proposed in this study. A set of mass balance equations was formed to calculate content of concrete compositions including cement, water, sand, and coarse aggregate. The degree of hydration of cement was taken into account in the analysis in order to cover the effect of age of concr...

Steel slag, which has low CaO content, is a by-product of steel processing. The steel slag consisting iron oxides is ground into sizes as coarse aggregates used for concrete. In this paper, the steel slag was characterized by chemical, physical and mineralogical analysis, and then the steel slag was used to replace 100% coarse aggregates in high st...

Waste glass has potential for use in building materials, for example, as an aggregate replacement, a filler in concrete, or a cement replacement. Finely ground glass powder (particle size of less than 38 μm) can be used as a pozzolan material in concrete because of its high reactive silica content. This paper studied the properties of concrete cont...

Fiber reinforced cementitious mortar (FRCM) systems, innovative strengthening systems, for repairing and strengthening concrete and masonry structures are an alternative option to traditional techniques such as fiber reinforced polymers (FRPs), steel plated bonding, and section enlargement. In this paper, a FRCM strengthening system made of polypar...

This study investigated the chloride binding isotherms of various cement types, especially the contributions of C-S-H and AFm hydrates to the chloride binding isotherms were determined. Ordinary Portland cement (OPC), Modified cement (MC), Rapid-hardening Portland cement (RHC) and Low-heat Portland cement (LHC) were used. The total chloride content...

Fine ground glass powder has the potential to be used as pozzolan materials in concrete because of the high amount of reactive silica. This paper studied about concrete properties using fine ground glass powder (approximate particle size 12-15 microns) with admixture Type D following ASTM C494. By studying the compressive strength development of co...

This paper presented the model to predict the chloride diffusion coefficient in tension zone of plain concrete under flexural cyclic load. The fictitious crack based analytical model was used together with the stress degradation law in cracked zone to predict crack growth of plain concrete beams under flexural cyclic load. Then, under cyclic load,...

The survival of a large number of buildings in southern Thailand with minor structural damage under 2–6 m inundation heights above the ground in the 2004 Indian Ocean tsunami tragedy suggests that it is necessary to calibrate the formulas stipulated by FEMA-55 [2000] for computing tsunami loadings. In this study, the weather monitoring building of...

Chloride induced corrosion is a concern that governs the durability of concrete structures in marine environments, especially in tidal environments. During the service lives of concrete structures, internal cracks in the concrete cover may appear due to imposed loads, accelerating chloride penetration because of the simultaneous action of environme...

Presented herein is a model to simulate the chloride ingress into plain concrete, using four common cement types, under flexural cyclical load and tidal environment. Flexural cyclic load was applied from 50 to 80% ultimate bending load, stress ratio (SR) = 0.5; 0.6; 0.7 and 0.8. Fictitious crack model was adopted to predict fatigue deformation of c...

This study investigated the chloride binding isotherms of various cement types, especially the contributions of C-S-H and AFm hydrates to the chloride binding isotherms were determined. Ordinary Portland cement (OPC), Modified cement (MC), Rapid-hardening Portland cement (RHC) and Low-heat Portland cement (LHC) were used. The total chloride content...

Mixing of solid particles, which can be obtained from concrete constituent, were studied as the original point to deal with the problem of mixing concrete. Since mixing of solid particles has been considered as a fully mechanical operation, mixing will never occur unless input energy is applied. Therefore, the electrical power consumed by the mixer...

An experimental program was conducted to investigate the shear-carrying capacity of precast prestressed hollow slabs with concrete topping. Ten specimens of the composite member without shear reinforcement were tested as simply supported beams with static two-point loading. The parameters investigated were prestressing force, thickness of concrete...

This paper presents and discusses the results of an experimental investigation of anchor bolt group embedded in unreinforced concrete, monotonically loaded in shear. All anchor bolts are embedded sufficiently to prevent concrete failure with pullout cone. Tests are conducted on single, double (loading in both normal and parallel to bolt line), and...

This investigation performed the chloride binding capacities of various cement types, especially the chloride binding isotherms of Calcium silicate hydrate (C-S-H) and Monosulfate (AFm) hydrates were specified. Ordinary Portland cement (OPC), Modified cement (MC), Rapid-hardening Portland cement (RHC) and Low- heat Portland cement (LHC) were used....