• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.2469-2475
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• 2014

In 1990s, with the increase of domestic building renovation but also increase the amount of anchor. The 45-degree cone failure theory has been used in concrete anchor bolts design, but the CCD (concrete capacity design) method was adopted as a new design method since 2000. However, the method has some problems because it is based on the experimental results of pre-installed concrete anchor bolts. In this study, the objective is to investigate the effects of anchor edge distance, anchor interval and concrete strength on pullout characteristics of post-installed concrete set anchor embedded in plain concrete.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.2
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• pp.367-375
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• 2014

Recently the use of concrete post-installed set anchors has been increasing because this constructing method is flexible and easy to attach or fix structural members when we repair, reinforce, or remodel a concrete structures. Depending on the shear strength of steel, the strength of concrete, edge distance and anchor interval, etc, the anchor loaded in shearing exhibits various failure modes such as steel failure, concrete failure, concrete pryout. In this study, the objective is to investigate the effects of the variations like anchor embedment depth, anchor interval, edge distance and concrete strength on the shear failure behavior of post-installed concrete set anchor embedded in concrete. The results of embedment depth experiments show that concrete strength has much effection on the shallow embedment depth. Steel failure occur to all results of the anchor interval experiments, but concrete is failed when edge distance experiments that less than the embedment depth. Through the comparision of the same parameters experiments results show that as strong as concrete strength are the displacement results are small.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.1
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• pp.40-47
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• 2014

Recently the use of concrete post-installed set anchors has been increasing because this constructing method is flexible and easy to attach or fix structural members when we repair, reinforce, or remodel structures. Accordingly, designers and builders of Korea depend on foreign design codes since there are no exact domestic anchor design codes that they could credit. The anchor in plain concrete loaded in tensile exhibits various failure modes such as concrete breakout, splitting, steel failure, pull-out and side-face blowout, that depending on the tensile strength of the steel, the strength of concrete, embedment depth, interval, the edge distance and the presence of adjacent anchor. The objective is to investigate the effects of the variations like anchor embedment depth, interval and edge distance on pull-out fracture behavior of post-installed concrete set anchor embedded in plain concrete.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.5
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• pp.31-39
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• 2013

In this study, performance of the post-installed anchor system was evaluated with reduced strength of concrete and anchor. One of the post-installed anchors was selected to performance evaluation. Concrete strength was reduced by freeze-thawing test, and the post-installed anchor strength was reduced by corrosion test. The post-installed Anchor was installed in concrete of freezing and thawing and original concrete, and corroded anchor was installed in original concrete only. Anchor diameter and installation depth of the anchor were the variable for each specimen. Performance of post-installed anchor system of each specimen was evaluated by pullout test. Anchor diameter and installation depth of anchor, it may affect the performance of the post-installed anchor system from the experimental test results. Fracture mode of each post-installed anchor system had occurred differently depending on the durability of concrete and anchor. The anchor pullout strength from the experimental test results was used in order to compare with the results of CCD (Concrete Capacity Design) method, and CCD equation was modified. Modified equation was able to predict the anchor pullout strength of post-installed anchor system in Original concrete and freezing and thawing of concrete.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.3
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• pp.55-63
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• 2015

Post-installed concrete set anchors are installed after the concrete hardened. These anchors increasing usage in development of construction equipment and flexible construction. The anchor loaded in shearing exhibits various failure modes such as steel failure, concrete failure, concrete pryout, depending on the shear strength of steel, the strength of concrete, edge distance and anchor interval, etc,. In this study, the objective is to investigate the effects of the variations like anchor embedment depth, edge distance and concrete strength on experimental and finite element analysis of shear failure behavior of post-installed concrete set anchor for light load embedded in concrete. The results of embedment depth experiments show that concrete strength has much affection on the shallow embedment depth. Concrete strength has no much affection with anchor interval and edge distance parameter and both experimental results occurred same failure mode. By comparing the experimental results that occurred steel failure mode show that as strong as concrete strength are the displacement results are small.

• Journal of Korean Society of Steel Construction
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• v.17 no.3 s.76
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• pp.271-283
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• 2005

This paper concerns the prediction of shear capacity, as governed by steel failure and concrete breakout failure, of set anchors installed in plain concrete. For this purpose, the methods to evaluate the shear capacity of the set anchors in concrete are summarized and the experimental data are compared with capacities by the two present methods : the method of ACI349-90 and the Concrete Capacity Design (CCD) method. (1) The constant-0.684 in the steel strength equation of set anchor was determined from shear test data at the 5 percent fractile probability. Consequently, it was concluded that the constant-0.6 and 0.5 in the steel strength equation for steel failure of ACI318-02 and EOTA were safe. The nominal shear strength of set anchor was proposed as following. $V_s=0.684 A_{se}f_{ut}$. (2) The CCD method was considered reasonable in estimating the concrete breakout strength of set anchors. In terms of the CCD method, the nominal concrete breakout strength of set anchor in shear was provided as follows; $V_b=0.609(\frac{\iota}{d_o})^{0.2}\sqrt{d_0}\sqrt{f_c}(c_1)^{1.5}$(N). (3) The CCD method was considered reasonable in estimating the concrete breakout strength for spacing of set anchors. The proposed equation was considered safe in estimating the concrete breakout strength for spacing of set anchors.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.10
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• pp.5237-5242
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• 2013

Recently, many bridges become not only functionally obsolete of bridge dick due to inadequate width but also structurally deficient of substructure due to erosion. In these case widening is almost always more economical than complete replacement, and therefore there is a need to make available the results of research and field experience pertaining to the widening of bridge substructure. But, an experimental study for the guarantee of unification between existing and new substructure with post-installed concrete set anchor is so insufficient that the development of post-installed concrete set anchor system for the unification should be settled promptly. The objective is to investigate the effects of anchor embedment depth and concrete strength on pullout characteristics of post-installed concrete set anchor embedded in plain concrete. The effects of embedment depth variable is depending on concrete strength as strong as concrete strength is pullout load is high. Regardless of concrete strength, embedment depth that less than 6 times appeared concrete failure mode but for embedment depth that over 8 times concrete strength has no affection on failure mode.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.129-132
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• 2008

All bearing device should be examined to determine that they are functioning properly. Small changes in other portions of the structure, such as pier or abutment settlement, may be reflected in the bearings. Bearings should be checked to see that they can move freely and are clear of all foreign material. Shoes should be in proper position relative to the temperature at the time of the inspection. Check anchor bolts for any damage and to see that nuts are secure. See that anchor bolt nuts are properly set on the expansion bearings to allow normal movement. In this paper, rehabilitation method for damaged bearings is proposed and damage example of the skewed bridge is illustrated

• Geomechanics and Engineering
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• v.27 no.6
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• pp.537-550
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• 2021

There are various technical problems need to be solved in the construction process of pre-setting an isolation wall into a double lane in the outburst prone mine. This study presents a methodology that pre-setting an isolation wall into a double lane without a coal pillar. This requires the excavation of two small section roadways to dig a wide section roadway, followed by construction of the separation wall. During this process the connecting lane is reserved. In order to ensure the stability of the separation wall, the required bearing capacity of the isolation wall is 4.66 MN/m and the deformation of the isolation wall is approximately 25 cm. To reduce the difficulty of implementing support the roadway is driven by 5 m/d. After the construction of the separation wall, the left side coal wall is brushed 1.5 m to make the width of the gas roadway reach 2.5 m and the roadway support utilizes anchor rod, ladder beam, anchor cable beam and net configuration. During construction, the concrete pump and removable self-propelled hydraulic wall mold are used to pump and pour the concrete of the isolation wall. In the process of mining, the stress distribution of coal body and isolation wall is detected and measured on site. The results demonstrate that the deformation of the surrounding rock of roadway and separation of roof in the roadway is small. The stress of the bolt and anchor cable is within equipment tolerance validating their selection. The roadway is well supported and the intended goal is achieved. The methodology can be used for reference for similar mine gas control.

• Steel and Composite Structures
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• v.44 no.1
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• pp.1-15
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• 2022

The weld quality has always been an important factor affecting the development of exposed CFT column-base joint. In this paper, a new type of exposed RCFST column-base joint is proposed, in which the high strength steel bars (USD 685) are set through the column and reinforced concrete foundation without any base plate and anchor bolts. Three specimens, the varying axial force ratio (0, 0.25 and 0.5), were tested under cyclic loadings. In addition, the bending moment capacity, energy dissipation capacity and deformation capacity of column-base joints were clarified. The experimental results indicated that the axial force ratio increases the stiffness and the bending moment and improves the energy dissipation capacity of column-base joints. This is because a large axial force can limit the slip between steel tubular and infilled concrete effectively. The specimens show stable hysteresis behavior.