Reinforcement Strain Research Articles

Interaction Strength of Hanger and Horizontal Steel Reinforcement of Dapped End Beams

The dapped end beam members have a special end with low depth at the support area, which results in a weak area against shear stresses. Classical structural analysis doesn’t capture the precise steel reinforcement interaction at the dapped zone area. The main objectives of this study are to investigate the strength of the dapped end area and to analyze stresses in the steel reinforcement to evaluate the shear failure mechanism at the re-entrant corner. The experimental tests conducted on RC beam samples, in addition to the numerical simulation of these samples by a finite element program, have been compared with a mathematical model. The experimental program highlighted the strains in the steel reinforcement in the dapped region to calculate the magnitude of the stresses in the steel reinforcement. In the experimental program, six dapped beams were fabricated with a length of 3 m, a width of 150 mm, and a depth of 300 mm. The notched end has a 150-mm depth and 150-mm height. These beams were loaded by a concentrated load near support to investigate the shear strength capacity. From the results for steel reinforcement strain, it is found that hanger and horizontal steel reinforcements interact to provide dapped end shear strength. The study proposes a new approach to computing shear strength capacity at the re-entrant corner by adding the contributions of the horizontal and hanger steel reinforcement using an appropriate proportion strain factor. This method revealed greater carrying capacity for the dapped end beam compared with other common structural methods. The results of the numerical analysis were done by the ABAQUS finite element program, showing the same behavior as the experimental work. This study proved the common contribution of hanger and horizontal re-entrant corner steel reinforcement and proposed a new formula to determine the updated nominal shear strength. Doi: 10.28991/CEJ-2023-09-12-015 Full Text: PDF

Investigating punching shear in slabs with unbalanced moments and openings

The impact of openings and moment transfer on punching shear resistance was investigated by conducting tests on nine interior slab-column connections measuring 2,400 mm square and 150 mm thick. The connections were subjected to different unbalanced moment orientations with eccentricities of 250 mm and 500 mm, and without shear reinforcement. The openings, located on the faces of the rectangular supports, had widths of either 200 mm × 200 mm or 200 mm × 300 mm. The study analysed ultimate loads, vertical displacements, flexural reinforcement strains, and concrete strains. The experimental punching strength was compared to theoretical predictions according to ACI 318:19, fib MC 2010:13, for different levels of approximation and the 2nd generation of Eurocode 2 prEN 1992-1-1:21. Observations are provided regarding the code’s calculation for slabs with openings.

Experimental Study on Structural Performance of Cast-in-Place Frame Printed Concrete Wall

A growing number of nations and regions have printed concrete structures thanks to the application of 3D printing technology in the field of civil engineering. However, the houses built with printed concrete are mostly printed concrete wall structures with composite load-bearing walls and cast-in-place frames. This structure solely takes into account the performance of the structure under vertical loads, which does not address its ability to withstand horizontal loads. In this paper, wall specimens were designed and tested under horizontal reciprocal loads in order to investigate the structural performance of this cast-in-place border-frame printed concrete wall structure under horizontal loads. Four factors are examined in order to determine how well the cast-in-place frame printed concrete wall structure performs when subjected to horizontal loads: column longitudinal reinforcement strain, hysteresis curve, skeleton curve, and energy dissipation capacity. According to the test results, the addition of the wall increased the bearing capacity and accumulated energy dissipation of the specimen, but the increase in stiffness also caused the structural ductility to decrease. As a result, cracks were more likely to generate at the wall–column joints, so the stiffness matching between the printed concrete wall and the cast-in-place side frame needed to be further coordinated to obtain a higher ductility. It turns out that the wall sections have little impact on the seismic performance of the members.

Study on the Bending Performance of High-Strength and High-Ductility CRE-Reinforced Concrete Beams

Constant resistance energy (CRE) steel reinforcement has a yield strength of up to 750 MPa and an ultimate elongation of more than 20%. CRE reinforcement overcomes the contradiction between high yield strength and high uniform elongation of ordinary high-strength bars. This paper explores the flexural performance and load-carrying mechanisms of CRE-reinforced concrete beams through a series of experiments, while also presenting a theoretical analytical method for such specimens. Flexural tests on six CRE-reinforced concrete beams and two control tests on hot-rolled ribbed bar 400 (HRB400)-reinforced concrete beams were conducted in this paper. The study examines the influence of the shear–span ratio and reinforcement type on the mechanical response of the beams, including cracking load, yield load, and ultimate load, while analyzing the variation patterns of concrete strain and reinforcement strain. The experimental results demonstrate that as the shear–span ratio decreases, the crack resistance and load-carrying capacity of CRE-reinforced concrete beams improve. Under equivalent conditions, CRE-reinforced concrete beams exhibit higher load-carrying capacity compared to HRB-reinforced concrete beams, surpassing the latter by approximately 43% in terms of ultimate load. Additionally, this paper proposes a calculation method for the mechanical response of NPR-reinforced concrete beams and compares the theoretical values with the experimental values. The differences between the two are within 13%, which proves the reliability of the calculation method.

Analytical method for evaluating the tensioned membrane effect in the geosynthetic-reinforced unsaturated embankment soil subjected to localized sinkholes

In karst regions, the occurrence of sinkholes is a common cause of roadway failures, leading to significant embankment deformation and instability. The advantages of geosynthetic reinforcement have been proven in practice in numerous countermeasures to lessen the impact of localized sinkholes, and associated design methodologies have been developed. However, some existing design methods assume there is no deformation in geosynthetics embedded in soils, and the effect of matric suction in soils is not considered either. This study suggested an analytical approach that took into account the strain in the geosynthetic reinforcements as well as the impact of matric suction. The developed design method was used to conduct parameter studies under various matric suction conditions. The method was validated against the experimental results, and the feasibility of the developed method was also compared with the existing design methods. The findings demonstrate that, in comparison to the method created here, existing design methodologies produce more conservative results. The strain and the deflection of the geosynthetic calculated using the suggested method are lower than those provided by the current design methodologies.

Effect of test parameters on the punching-shear strength of precast tunnel segments reinforced with GFRP bars

While assessing the load cases is crucial for designing the precast concrete tunnel lining (PCTL) segments, none of the tunnel-specific standards or codes explicitly consider punching-shear loads. This study aimed at determining the structural performance of full-scale precast concrete tunnel segments reinforced with glass fiber-reinforced polymer (GFRP) bars. The segments were constructed with a rhomboidal shape measuring 2100 × 1500 × 250 mm and subjected to point loading on their extrados surfaces until failure. Such loading simulates the geotechnical exposure conditions surrounding tunnels, such as rock expansion. The effects of concrete strength and GFRP flexural reinforcement ratio on the punching behavior were analyzed and are discussed herein. The load–deflection response, failure mode, punching strength, cracking behavior, reinforcement and concrete strain, deformability, and energy absorption were all evaluated in the experiments. The results reveal that increasing both the flexural reinforcement ratio and concrete strength enhanced the punching response and decreased crack width. In addition, using HSC in tunnel segments yielded higher pre-cracking stiffness, punching-shear capacity, and energy absorption. A theoretical investigation involving a comparison between predictions of the FRP-reinforced concrete slab design provisions and experimental results was performed to assess the applicability of the current punching equations for PCTL segments. The equations in the FRP-reinforced concrete codes predicted the punching capacities conservatively, while the researchers’ proposed equations overestimated. Moreover, CAN/CSA S806-12 showed the most accurate prediction of the punching capacity even if the concrete compressive strength exceeded 60 MPa.

Effect of load details of the successive explosions on the blast behaviors of reinforced concrete beams

SummaryThe objective of this study was to study the effect of load details of successive explosions on the blast behaviors of reinforced concrete (RC) beams. First, the effect of the successive loading of two identical explosions was discussed by considering the influences of standoff distance, charge mass on the failure states, and structural responses (displacement and support reaction force). And keeping the total TNT charge mass of 1 kg unchanged, the effect of loading numbers was investigated by loading two 0.5 kg TNT successively and a single 1 kg TNT on RC beams, respectively. Besides, the successive loading of two different explosions was also considered by investigating the effects of loading sequences and the first explosion induced pre‐damage on the ultimate accumulated damage of RC beams. At last, based on the reaction force and displacement responses, a nonlinear relationship between the dynamic residual load‐carrying capacity and the accumulated residual displacement was obtained to assess the damage states of the tested beams. The results show that the local failure range along the beam span direction (length of peeling‐off and length of spallation) caused by the first blast load did not apparently increase when the damaged beams were subjected to another blast load. With the increase in explosion numbers, depth of compressive crushing increases gradually. At the same stand‐off distance (from 0.25 to 0.45 m), due to the damage accumulation effect, successive loading of two 0.5 kg TNT can trigger more severe local failure but smaller accumulated residual deflection to beams than the single loading of a 1 kg TNT. Besides, when two different blast loads are loaded on tested beams, the loading sequence of the larger one first and then the smaller one (1 kg TNT/0.5 kg TNT at h = 0.45 m) can trigger larger damage to beams than the opposite loading sequence (0.5 kg TNT/1 kg TNT at h = 0.45 m). And for the beams subjected to a smaller blast load first and then a larger one, a stiffer behavior may be triggered by the second blast load on the beam after the first loading of the smaller blast load due to the residual strain in longitudinal reinforcement. Furthermore, based on the nonlinear relationship between residual load‐carrying capacity and residual displacement, the accumulated damage of RC beams was divided into mainly four phases.

Precast segmental beams made of fibre-reinforced geopolymer concrete and FRP tendons against impact loads

In the open literature, there is no investigation into the impact behaviour of prefabricated segmental concrete beams (PSCBs) cast with low CO2-emission fibre-reinforced geopolymer concrete (GPC), reinforced with non-corrodible basalt fibre-reinforced polymer (BFRP) reinforcement, and post-tensioned with carbon FRP (CFRP) tendons. This research, hence, aims to close this existing gap of knowledge. The primary goals are to investigate the effect of dispersed fibres on the impact response of PSCBs and to compare the performance of CFRP versus steel tendons. The experimental results reveal that the PSCBs fail due to excessive joint openings that lead to concrete spalling and flying concrete debris. The inclusion of dispersed fibres in the concrete postpones crack development, reduces reinforcement strain, and effectively mitigates concrete spalling and stiffness degradation of the beams. While fibres show limited influence on the deflection response of PSCBs, as the deformation of segmental beams is predominantly governed by joint openings with no fibres bridging across the joints, they play a crucial role in preventing severe damage during impact events. The impact response of beams post-tensioned with CFRP tendons is analogous to those with steel tendons. Notably, both the CFRP tendon and BFRP reinforcement remain intact even when the beam fails under impact loads. This implies that CFRP tendons and BFRP reinforcement can be successfully employed in constructing durable and sustainable segmental GPC beams capable of withstanding impact loading. A high-fidelity numerical model of PSCBs made of GPC and FRP tendons and reinforcement subjected to impact loads is also developed, for the first time, to supplement the discussions of experimental findings.

Evaluation of recycled concrete aggregate in reinforced concrete elements under simulated corrosion conditions utilising diverse non-destructive methods

ABSTRACT In this study, the performance of recycled concrete aggregate (RCA/RSA) available in Agartala, Tripura (north-eastern regions of India), was studied in reinforced concrete members subjected to a severe artificially induced corrosive environment. The performance test was based on the non-destructive and destructive parameters of concrete. Due to the scarcity of normal stone aggregate (NSA) in this region, studying the effect of using such type of aggregate in reinforced concrete members help not only to mitigate the demand but also assists in waste management. The study also presents an innovative application of micro-bend opticalfibre sensors for corrosion monitoring and validated using other non-destructive instruments. The study presents an effective application of the micro-bend optical fibre sensor to predict the initiation of corrosion (de-passivation) and initiation of cracking (critical stress) due to corrosion in reinforced concrete specimens. Later, the results were validated using half-cell potentiometer and electrical strain gauge values. The specimen also presented different mechanical and durability properties with varying RCA percentages. A regression model to predict mechanical properties and corrosion amount (hoop strain) in reinforcement for different RCA-replaced concrete has been presented. The sorptivity and other porosity-related results were also presented for different RCA replacement percentage specimens.

Numerical simulation and theoretical analysis on RECC ring beam joints for RECC-encased CFST composite columns

The failure mechanisms of reinforced engineered cementitious composite (RECC) ring beam joints were numerically analysed using finite element (FE) software of ATENA. The failure mode, load-carrying capacity, ductility, and distribution of the strain in the steel reinforcement were comprehensively investigated. The simulation results showed that the RECC ring beam significantly contributed to the mechanical property of the joint. Part of the circumferential reinforcement in the ring beam contributed to the shear strength and improved the strength of the core ECC by the restraint effect. A total of 46 specimens were subsequently investigated to examine the influences of the circumferential reinforcement ratio, stirrup ratio, axial compressive ratio, tensile properties and compressive strength of ECC on the seismic behaviour of RECC ring beam joints. Finally, a simplified softened strut-and-tie model was proposed to predict the shear-carrying capacity of the RECC ring beam joint.

Finite element analysis of compaction load to investigate the stress-deformation behavior of soil geosynthetic composite mass: A case study

When building Soil Geosynthetic Composite (SGC) walls, fill compaction is normally carried out by operating a compactor in a general direction parallel to the wall face. In other words, a moving point or area load is often used to apply a compaction load on a newly installed soil lift. Pham (2009) and Wu and Pham (2010) demonstrated that the compaction-induced stress (CIS) caused by multiple passes of a compactor moving toward or away from a section can be calculated by taking into account the compaction load applied directly above the section under consideration using a simplified stress path proposed by Duncan and Seed (1986). Additionally, by simulating the compaction, the CIS due to fill compaction may be correctly assessed. The CIS resulting from fill compaction can also be accurately assessed by simulating the compaction load, such as by applying a distribution load on top of each backfill layer or a distribution load at the top and bottom of each soil layer, or by applying various widths of strip load to the top of each backfill layer. The objective of this study was to validate the numerical simulation of the compaction load to stress deformation behavior of SGC mass under operating stress conditions. In order to conduct the numerical analysis, data from both a full-scale instrumented SGC mass based on large-scale soil geosynthetic composite (SGC) experiments and a 6 m-high SGC (Pham, 2009) were employed. This study will examine a few SGC behavior parameters, including reinforcement strains, lateral displacements, and reinforcement strains. The objective of the FE modeling is to demonstrate the effect, emphasize the significance of the compaction conditions to the stress-deformation behavior of SGC mass, and validate the findings from the field-scale experiments and proposed model by Pham (2009) and Wu and Pham (2010).

Analytical Investigation on Catenary Action in Unbonded Prestressed Concrete Beam-Column Subassemblages

One reinforced concrete (RC) and four prestressed concrete (PC) beam-column subassemblages with various tendon profiles were designed and tested to investigate the effect of prestressed tendon profiles on the progressive collapse response of PC frames. An analytical model was developed to evaluate the PC frames’ catenary action (CA) response by identifying the fracture of longitudinal reinforcement and prestressed tendons in beams. The effect of the bond mechanism on the rupture strain of reinforcement was considered. Then, the proposed model was validated using experimental and simulation results. Finally, parametric studies were performed based on the calibrated model. Test results indicate that the prestressed tendon profile significantly impacts the CA response of PC frames against progressive collapse. The analytical model can effectively reflect the effect of the prestressed tendons on the CA resistance and displacement of PC frames.

Effects of reinforcement connection types and loading angles on prefabricated concrete column seismic performance

This study aimed to determine the seismic performance differences between prefabricated concrete columns with grouted sleeves (PCgs columns) and prefabricated concrete columns with slurry anchors (PCsa columns), as well as the effect of different horizontal loading angles on the seismic performance of PCgs columns. In addition to a control cast-in-place column (CIP column), three PCgs columns and one PCsa column were planned and manufactured as precast concrete column specimens. All samples were made with the same reinforcement, hoop rate, and concrete strength. Static tests were used to test the impacts of various loading angles and reinforcement connection forms on the damage morphology, hysteresis curve, skeleton curve, energy dissipation, stiffness degradation, ductility, and reinforcement strain of each specimen. The experimental results were validated, and the phenomenon was further explored by performing a finite element analysis of the model and then performing the calculations in XTRACT software. The results indicate that the loading angle significantly impacts the seismic performance of PCgs columns. As the horizontal loading angle increases, the peak bearing capacity of PC columns decreases while the flexural bearing capacity increases and then decreases. The initial cracking location of PCsa appears in the middle of the pre-buried bellows; compared with the CIP column under the oblique 45° loading angle, the reinforcement connection method has a greater impact on the seismic performance of PC columns under the same loading angle; compared with the CIP column under the low circumferential reciprocal cycle, the development of cracks in PC columns body is less, and the later crack development is concentrated at the connection joints; the most unfavorable sections that may occur are the connection joints, the section at the joint at the bottom of the column has a high shear bearing capacity and positive section compression bending failure occurs.

Experimental investigation on the damage evolution and failure mechanism of segmental joints based on DOFS and AE

The damage evolution and failure mechanism of segmental joint are of great significance for the design and safety assessment for segment structures. In this study, a series of full-scale loading tests on the segmental joints adopted by the Jinan Yellow River Tunnel under positive bending loading scenario (PBLS) and negative bending loading scenario (NBLS) were conducted, introducing new measurement scheme combining distributed optic fiber sensor (DOFS) and acoustic emission (AE). The joint deformation, AE parameters, concrete strain, bolt strain and reinforcement strain are investigated. The test results show that the deformation and failure process of the joint can be divided into four stages and three stages under PBLS and NBLS, respectively. The compression-shear failure caused by the shear cracks is considered as the main failure mode of the segmental joints, and the development rate of the crack width under PBLS is obviously larger than that under NBLS. The maximum bolt strain usually occurred at the edge of the thread instead of the joint surface. The bolt under NBLS yields later than that of PBLS. Due to stress concentration, the maximum tensile strain of reinforcement under PBLS and NBLS is located near the hand hole and sleeve, respectively.

Experimental and Numerical Study of the Flexural Performance of Spontaneous Combustion Gangue Coarse Aggregate Concrete Laminated Slab

(1) Background: to study the differences in flexural performance and failure characteristics of spontaneous combustion gangue coarse aggregate concrete (SCGAC) laminated slabs and ordinary concrete laminated slabs, comparative flexural performance tests of one ordinary concrete laminated slab and four spontaneous combustion gangue coarse aggregate concrete laminated slabs (SCGACLSs) full-scale specimens were carried out. (2) Methods: The loading method was four-point unidirectional static loading; the failure mode, load–deflection curve, load–reinforcement strain curve, and load–concrete strain curve of each specimen were analyzed. In addition, the load–deflection curve of the five slabs were predicted by ABAQUS. (3) Results: The five laminated slabs showed similar behaviors in terms of failure mode, load–strain curve, load–deflection curve, and deformation and all the properties satisfied the Chinese standard GB50010 (2010). Compared with ordinary concrete laminated slabs, the cracking load of SCGACLS with a precast layer of SCGAC(C30) decreased by 15.2% and the span deflection increased by 28.3% in the ultimate condition; however, when the strength grade of SCGAC of the precast layer was increased to SCGAC(C40), the cracking load increased by 7.8% and the span deflection was similar to that of the ordinary concrete laminated slabs. All specimens conformed to the planar section assumption. In addition, the finite element model (FEM) prediction results showed that the maximum relative errors of load and deflection were <5% and <10%, respectively, indicating that the established FEM had high prediction accuracy. (4) Conclusions: The defects of reduced load-carrying capacity and uncoordinated deformation caused by the different elastic modulus of precast and cast-in-place layer concrete can be compensated by appropriately increasing the strength grade of precast layer concrete of SCGACLSs. The application of SCGACLSs in structures is feasible.

Experimental and Numerical Comparative Study on RC Beam Flexurally Strengthened with CFRP Laminate.

In this article finite element model is prepared for reinforced concrete beam which is flexurally held together by means of carbon fiber reinforced polymer laminate. The 3D analysis is conducted using ABAQUS software and the results are investigated, where maximum load, deflection at mid span and strain characteristics of both reinforcement and concrete are analyzed numerically. Later these parameters are investigated experimentally in a similar way by keeping all the important conditions such as loading, reinforcement detailing, boundary condition etc. identical. This comparative assessment illustrates that, the using of CFRP has a significant advantage to improve flexure behavior of RC beams. Various types of failure mode such as deflection and stress for whole cross section and for only reinforcement are achieved from finite element analysis. In addition, typical deflection, stress and strain contours of a specified node are found for unstrengthen and CFRP strengthened beam. This article also represents both the reinforcement strain values and concrete strain values for strengthened and unstrengthen RC beams and found a precise similarity while comparing with finite element modelling results. Furthermore, in terms of ultimate load, the deviation in result is as narrow as 4% for flexurally strengthened reinforced concrete beam by CFRP laminate. IUBAT Review—A Multidisciplinary Academic Journal, 6 (1): 13-24

Flexural behaviour of recycled reinforced concrete beams strengthened/ repaired with CFRP laminates

This research deals with the flexural performance of reinforced concrete beams which contain Recycled Concrete Aggregates (RCA) and were strengthened by Carbon Fiber Reinforced Polymers (CFRP). For this purpose, seven Reinforced Concrete (RC) beams were manufactured using RCA as a replacement of Normal Coarse aggregates (NCA) with percentages of (0%, 25%, 50%, and 100%). The cross-section of all beams was 150 × 300 mm and 2100 mm overall length and with loaded span of 1800 mm. Firstly four beams (group A) with different RCA ratios were loaded in a four-point loading configuration until failure. Secondly three beams (group B) were loaded to 30% of its ultimate load after that group B beams were strengthened using CFRP laminates on the lower face of the beams to be strengthened to resist flexural stress. Crack pattern, initial cracking load, ultimate load, mid-span deflection, and strain in main reinforcement were monitored. The results show that increasing RCA ratios generally leads to decreasing in the ultimate loads, for RCA ratios of 25%, 50% and 100% the decrease in beams ultimate load was with ratios 4.8%, 25.5% and 26.8%, respectively compared to control beam (0% RCA). The preloaded beams that were repaired with CFRP laminates have higher ultimate loads than beams without CFRP laminates and lower mid span deflection at maximum load (for instance repaired beam with 50% RCA ratio with CFRP laminate has shown higher ultimate load with 56.6% and less deflection with 36.9% compared to its corresponding unstrengthen beam).

Compression behavior of GFRP reinforced hybrid fibre reinforced concrete short columns subjected to eccentric loading

This paper presents the results of an experimental study carried out on the GFRP reinforced hybrid fibre concrete short columns subjected to eccentric compression. In this study, hybrid fiber-reinforced concrete was prepared in different volume ratios of hybrid fibers and the cooperative effect of the GFRP reinforcement and the steel-PVA hybrid fibre concrete with different fibre ratios under eccentric loading was explored. 10 GFRP reinforced hybrid fibre concrete short columns and 2 plain reinforced concrete short columns were tested to investigated their eccentric compressive properties. The tests results are presented in terms of failure modes, longitudinal reinforcement strain, concrete compressive strain and compressive load capacity of GFRP reinforced hybrid fibre concrete eccentrically compressed short columns. The results show that the concrete on the compressed side was crushed when the specimen under both the initial eccentricity of 50 mm and 100 mm the reinforcement were pulled on the tension side of specimen under a larger initial eccentricity of 100 mm. The addition of fibres can effectively prevent the crack generation and development and improve the bonding property between reinforcement and concrete. Besides, the addition of steel fibre contributes a better performance on the ultimate compressive capacity of specimen under a lager initial eccentricity with an optimal ratio of steel fibre at 1.4 %. PVA fibre effectively improve the ductility of the concrete, so that the hybrid fibre concrete elements remain relatively its integrity after failure. Finally, considering the effect of GFRP reinforcement and different ratios of steel fibre and PVA fibre on the compressive capacity of short concrete columns, the equation for the calculation of the ultimate compressive capacity of partial sections of eccentric columns is proposed, and a good agreement was observed between the tested and calculated value.

Experimental Study and Discrete Analysis of Compressive Properties of Glass Fiber-Reinforced Polymer (GFRP) Bars.

Glass fiber-reinforced polymer (GFRP) has superior characteristics over traditional steel, such as lightweight, high strength, corrosion resistance and high durability. GFRP bars can be a useful alternative to steel bars in structures, specifically those in highly corrosive environments, as well as structures subjected to high compressive pressure such as bridge foundations. Digital image correlation (DIC) technology is used to analyze the strain evolution of GFRP bars under compression. It can be seen from using DIC technology that the surface strain of GFRP reinforcement is uniformly distributed and increases approximately linearly, and brittle splitting failure of GFRP bars happens due to locally occurring high strain at the failure stage. Moreover, there are limited studies on the use of distribution functions to describe the compressive strength and elastic modulus of GFRP. In this paper, Weibull distribution and gamma distribution are used to fit the compressive strength and compressive elastic modulus of GFRP bars. The average compressive strength is 667.05 MPa and follows Weibull distribution. Moreover, the average compressive elastic modulus is 47.51 GPa and follows gamma distribution. In order to verify that GFRP bars still have certain strength under compressive conditions, this paper provides a parameter reference for their large-scale application.

EVALUASI KINERJA PILAR JEMBATAN LEMAH IRENG II BERDASARKAN PERFORMANCE BASED SEISMIC DESIGN

Lemah Ireng II Bridge is a type of box girder balance cantilever bridge located in Semarang Regency, Central Java, which was completed in 2014. The renewal of bridge loading regulations in 2016 consisted of SNI 1725:2016 for standard load and SNI 2833:2016 for earthquake load. Changes in earthquake loading regulations resulted in an increase in the ground surface spectra value in the short period (Sds, T=0,2 second) in the longitudinal direction by 38.47% and in the transverse direction by 45.39% as a result of updating the earthquake map and the earthquake response modification factor. To determine the level of bridge performance against the applicable earthquake regulations based on the pier structure parameters, the Non-Linear Time History Analysis (NLTHA) method is used. The NLTHA method uses seven deaggregated ground motion records which aim to represent the ground motions that occur at the bridge site. Parameter limits at the pier to determined performance level of bridge based on NCHRP Synthesis 440 and NCHRP Research Report 949. According to the results of performance-based analysis, the bridge pier structure meets the Fully Operational performance level based on the parameters of drift, compressive strain of concrete and tensile strain of steel reinforcement. At this level of performance, after an earthquake the structure suffers very little damage so no repairs are needed and the bridge can function immediately after the earthquake.