In this study, Rebar of SD500, SD600 is applied to the designed or constructed in domestic apartment. Analyzed the variation of the rebar according to the strength of the rebar and the construction cost of the change. Reinforced volume reduction of the apartment building is less than the other. Because, A low wall of rebar reduction is more than 50% of the total. The reason for the previous, Reduction of the quantity of horizontal reinforcement does not appear and Vertical rebar reinforcement than the stress is determined by the placement of rebar in which the upper floor.
Shear test on hollow-core slabs that using board-type lightweight materials is performed. Lightweight materials are positioned in the slabs, it separate into two parts vertically. It is possible that each parts act independently and the concrete columns, in the middle of slab, can resist this action. Thus we have to check horizontal shear force on part-column connection besides vertical shear force. Also effective cross-sectional area shear force which is considered by existing study is checked.
In this technology, To improves the performance of deflection of the slab reduces floor impact noise in downstairs without structural work in vulnerable to floor impact noise in Aged Apartment Houses. The finite element analysis results showed the performance improvement of slab when compared with the existing technologies and Predict the result of the excellent affordability and constructability.
In this study, Rebar of SD500, SD600 is applied to the designed or constructed in domestic underground parking. Analyzed the variation of the rebar according to the strength of the rebar and the construction cost of the change. Most of underground parking appear reduction of Rebar ratio. In this case, the load acting on the underground parking garage is large. So, Rebar placing is dominated by element's stress. Therefore, Large amounts material of slabs, beams and foundations are reduced. In case of columns and wall, Ratio of Material reduction is less than former. Because Splice and Anchorage of rebar amounts are increased and Hoop and horizontal rebar amounts are fixed. Percentage of rebar of the column and wall are 15%. So, Showed a less impact on the reduction of total material.
Strength bar has merits in workability improvement, construction time shortening and connection details to be easy. But, lap splice length tends to be longer. In this study, high strength threaded bar will be reviewed whether it is appropriate in domestic standards by KCI concrete structural criteria and propose the mechanical splice.
Recently, a market of architecture is requiring buildings of long spanned structures as most buildings become taller and larger. For being long spanned structures, elements of buildings must be light. As an alternative proposal, various hollow-core slabs and flat plate salbs were developed and used frequently in the inside and outside of the country. But the study of the hollow-core slabs using deck plate and assembly of light weight is the first. In the present study, Flexural and vibration tests were performed on the hollow-core slabs using deck plate and assembly of light weight to investigate the flexural behavior and serviceability. Four test specimens were used for test parameters; one hollow-core slab with an assembly of light weight, and three hollow-core slabs with deck plate and an assembly of light weight. The test parameters also included amount of tension bar and existence of shear reinforcement. The test results showed that the hollow-core slabs with deck plate and an assembly of light weight had a crack of shear, so shear reinforcement must be conducted.
Recently, practical application of high tension bar is attempted. The main object of using high tension bar is strengthening of material property and decreasing of steel amount. If using high tension bar which is not a definite yield strength,according to strain ratio of high tension bar tensile and compressive dominate mode ciearly, there being a possibility dividing becoming difficult. Specially, Providing steel ratio of balanced destruction is very difficult. In this study, high tension bar to apply to flexural member and the behavior experiment bending after one, will consider high tension bar the application possible standard of existing.
Most of the school buildings were built before the seismic code was established. To consider the sunlight and ventilation to the partition walls are built about 1m height beside columns at typical school buildings. For the reason, columns which is consisted school building occur brittle failure shape by the reduced effective depth. In this study, experimental test for retrofitting effect by Aramid Fiber Reinforced Polymers(AFRP) strips on masonry infilled reinforced concrete(RC) frames is performed. The test results were to ensured enough time to evacuate due to the enhancement of ductility and strength of school buildings to withstand earthquakes using AFRP strips .
A improved strength model was developed to predict the punching shear strength of interior slab-column connections without shear reinforcement. Considering the damage due to flexural cracking at slab-column connections damaged by flexural cracking, the punchingshear force was assumed to be resisted mainly by the compression zone of the critical section. The punching shear strength was defined by using the material failure criteria of concrete. In the evaluation of the punching shear strength, the interaction between the shear stress and the compressive normal stress developed by the flexural moment of the slab was considered. The proposed strength model was verified by existing test specimens.
LCVA has an advantage that its natural frequency can be easily controlled by changing the area ratio of the vertical column and horizontal part. The previous studies investigated the dynamic characteristics of the LCVA under harmonic load. This study experimentally obtained the first and second mode natural frequencies of the LCVA from shaking table tests using white noise and compared the values with the ones by previous study. Test results show that the measured first mode natural frequency of the LCVA is larger than the calculated one when the area ratio is larger than 1. The second mode frequency increases with the increasing area ratio, which is due to the sloshing motion effect resulting from the large area of the vertical column.
In order to obtain the flexural and shear performance capacity of newly developed WAffle Slab(WAS) System, 14 full-scale 1.98mx10.00m specimens were tested under monotonic load. The Flexural performance was observed and compared with the conventional double-tee slab system using the test result. The shear performance was observed W AS slab using the test result. lt was confirmed that WAS system has enough flexural and shea capacity to carry the design load. Destruction features of test result, it appeared with bending destruction on the whole. According to steel wire increase, tolerance force's also increased. But steel wire increases to follow, it appears brittle destruction aspect. Case of shear test, the stirrup interval to be narrow maximum load appeares the tendency which comes to be destroyed.
In order to identify the exact behavior of corbel section, the horizontal force acting on corbel section should be considered as well as the vertical force. In this study, a new corbel section, which is economical and easy to construct, is developed by evaluating the exact strength of the section. Experiments were performed to verify the strengths of the proposed sections comparing with those of the currently used section. The summary of the experiment results are as follows: 1) In order to minimize the horizontal force effect, it was found that the use of pre-stressing was most effective, and that TB type corble section is a most efficient section in terms of economy and workability. 2) The experimentally obtained strength of corbel section matched well with that estimated using shear friction theory. Therefore, it is concluded that shear friction theory would be very useful if a precise crack angle in the corble section, which is pre-stressed by PS strings and threaded bolts, is available.
In recently, the method estimated construction's defeat using the infrared thermography was prefer to method of new repair and estimate as a good point that simple of application and save labor, what is more economic than other techniques and can reduce need time. The purpose of this study is to develope the technique to measure the corrosion of reinforcing bars using the infrared thermal photography graphic data. In this page, the former final purpose establishment that galvanic corrosion method of reinforced bars and infrared thermography system, and studied trend of thermography and photography graphic data by parameters of corrosion of specimens, atmosphere temperature, concrete cover depth etc.
Corrosion level of reinforcing bar is investigated in this study. Seventy-two specimens are designed with 12 different target corrosion levels, two types of reinforcing bars, 3 different concrete covers. Corrosion current density, corrosion potential and ohmic resistance of concrete are measured on these specimens using Gecor device. Metal loss measurements are performed in accordance with ASTM G1-90[1], method C3.5[2], after specimens cracked. The actual corrosion weight loss of the steel reinforcing bars is then compared to the result obtained from the corrosion level measurement. Finally, the estimation of corrosion level can be made using electrical potential and current intensity measured. The experimental results show that the actual corrosion levels of steel bars embedded in concrete are less than the expected corrosion levels. And non-destructive corrosion measurement technique is applicable in order to assess corrosion level in reinforcing bars. This study suggests the relationship between corrosion level and measured electrical potential and measured current intensity.
Recently the construction of residential building faces many difficulties due to the shortage of building materials and works. Simplifying the stage of processing and assembling reinforcing rods and increasing the efficiency of them in reinforced concrete construction can be used to settle the difficulties. In the respect, structural wire-fabric is utilized. The purpose of this study, instead of deformed steel bars, to examine the utilization of slab joint, which is accompanied with a large deformation in the structure subjected to seismic loads, to suggest reinforcing method which is efficient, easily constructible and structurally safe. The results are as follows ; 1. The ductility capacity of slab reinforced by welded wire fabric was less than with deformed bar in discontinuous slab joint. To enhance the ductility capacity, deformed bar should be used with welded wire fabric for the longitudinal reinforcement. 2. It is avoid to use loop welded wire fabric as the longitudinal reinforcement in wall, because the strength and ductility capacity showed lower value than that with deformed bar. 3. Using welded wire fabric in wall structures, it need deformed bar reinforcement with sufficient anchorage length.
Recently, there has been a tendency to use composite deck plates in high-rise building and apartment construction due to its cost efficiency and less installation time. The purpose of current study is to clarify structural performance of deck plate and further safety through carefully designed experimental program. In order to clarify bending capacity and joint continuity, specimens were divided for positive and negative moment and testing parameters are thickness of deck plate, slab thickness, and various reinforcements The results of experimental test are following; (1) When the thickness of deck plate is 1.0mm, the strength increased by 1.3~10.1%, and 2.0~3.5% comparing the case of 0.8mm deck plate thickness. The thickness of deck plate did not play significant role in terms of strength of the slab in both positive and negative moment tests. (2) The yield strength of slab in positive moment test, having 200mm slab thickness and D13 reinforcement steel, was increased by 28.4~34.8% comparing 160mm slab thickness and D10 reinforcement steel case. And 22.4~25.1% of yield strength was increased after install bottom reinforcement steel. (3) In negative moment test results showed that the increase of yield strength when the bottom reinforcement installed was 2.0~2.3% in 200mm slab thickness and 2.0~3.0% in 160mm slab thickness. In positive moment test, the increase of yield strength was 22.8~26.7% in 200mm slab thickness due to bottom reinforcement, and 11.4~20.5% in 160mm slab thickness. The reason being bottom reinforcement in negative moment contributes less amount of yield strength compare to positive moment location is that the bottom reinforcement resists compression force where the deck plate has enough strength already.
Recently the construction of residential building faces many difficulties due to the shortage of building materials and works. Simplifying the stage of processing and assembling reinforcing rods and increasing the efficiency of them in reinforced concrete construction can be used to settle the difficulties. In the respect, structural wire-fabric is utilized. The purpose of this study, instead of deformed steel bars, to examine the utilization of slab joint, which is accompanied with a large deformation in the structure subjected to seismic loads, to suggest reinforcing method which is efficient, easily constructible and structurally safe. The results are as follows ; 1. The ductility capacity of continuous slab joints reinforced by welded wire fabric is less than that with deformed bar. But continuous slab joint is reinforced by deformed bar for the longitudinal reinforcement, it is increase strength and ductility capacity. 2. It is recommended that simple cut jointing of welded wire fabric should be avoided in wall-wall joints.