This study investigates the pore structure of cement paste after exposing to elevated temperatures, up to 800°C. The variation of pore structure of each sample was monitored for 180 days by mercury intrusion porosimetry (MIP). Test results showed that the increase of heated temperatures causes the increase of the size and volume of pores, which is probably due to the dehydration of hydration products, such as calcium silicate hydrate and calcium hydroxide.

Based on IoT (Internet of Things) where its concept contains providing convenience to human life by connecting every objects around us, numerous projects have been done in civil engineering field. This paper has conducted the basic study on adopting IoT sensing technology and network system into harbor.

In this study, to evaluate the performance of fire resistance of the mortar with magnesium hydroxide(MH) and aluminium hydroxide(AH) which has a RCC (Radiant Control Capability) as repair material to the steel structure, temperature evaluation of mortar was conducted by increasing 500°C in the furnace. The performance of RCC can decrease a temperature to external and internal mortar. As a result, it is confirmed that temperatures of mortar with magnesium hydroxide(MH) and aluminium hydroxide(AH) were more decreased than general mortar due to the RCC effect of MH and AH. Therefore, it can be possible to apply to a repair material at the steel structure.

Membrane structure is a system that is stabilized by maintaining a tensile state of the membrane material that originally cannot resist the bending or pressure. Also, it is a system that allows the whole membrane structure to bear external loads caused by wind or precipitation such as snow, rain and etc. Tension relaxation phenomenon can transpire to the tension that is introduced to the fabric over time, due to the innate characteristics of the membrane material. Thus, it is important to accurately understand the size of the membrane tension after the completion of the structures, for maintenance and management purposes. The authors of this paper developed the new portable measurement equipment by using sound wave and measured the tension of pre-existing membrane structure for its maintenance by using the equipment. Through analyzing the measurement data, the authors propose the points that should be improved and the technical method for the new maintenance system of membrane tension.

Measurement of dynamic displacement of large structure is one of the most challenging issues in structural health monitoring. With a Kalman filter based technique, the proposed displacement measurement system which consists of GPS-RTK, accelerometer, DAQ, and computer shows the huge potential for precise measurement of dynamic displacement of large structure. The performance of the system has been verified by modal shaker test. This paper presents a new system for dynamic and pseudostatic displacement measurement for a large-scale civil infrastructure. Even though dynamic displacement measurement on a large-scale structure is one of the most challenging issues in structural health monitoring, traditional displacement sensors as well as cutting edge noncontact sensors suffers from the lack of accuracy and precision due to field conditions such as measurement distance and requirement for a fixed support. With a Kalman filter based technique, the proposed displacement measurement system, which consists of a GPS-RTK, accelerometer, DAQ and computer, efficiently estimates bias contained in the acceleration record by fusing the acceleration with intermittently recorded GPS-RTK data, and estimate high precision and high accuracy displacement by removing the bias from the acceleration record and conducting double integration. Through a series of lab-scale tests using a vibration exiciter, the performance of the system has been verified and shows the potential for accurate and precise measurement of dynamic displacement of a large-scale structure.

This paper introduces unfamiliarity index (UFI) that calculated from the FFT results of the short term timeline acceleration responses. If this algorithm, which can detect an abnormal behavior from the maximum constant signal, is used to the terminal sensors of an structure, more accurate safety control criteria will be prepared efficiently.

In this study, the image processing technique referred as night vision was introduced in order to measure the displacement of structure during the nighttime. The validation of the reliability and the applicability of proposed method was evaluated by the scaled model test.

In this study, to evaluate the applicability of VDMS(Vision-based Displacement Measurement System) in the field, 30m of real specimens were measured vertical displacement using the VDMS and a displacement Transducer. The VDMS was to take a picture by attaching Target on the structure. Then, by analyzing the video in Digital Image correlation algorithm obtained a displacement of the structure. The vertical displacement of 30m real specimens using the VDMS and a displacement Transducer was very similar, and it is determined that the VDMS has a high applicability in the field.

This study results the shear capacity of a wall depending on the postion and reinforcement of the equipment opening using finite element analysis. Analysis results show that when the openings are placed in the corner, the shear capacity was reduced than in the center. and reinforcing with a steel sleeve can compensate for the reduced strength

As development of the construction technique, new composite material has been developed and research on structures made of this material is needed recently. In this study, curved composite laminated frame structure with four ply is analyzed using shell elements. There are six angle change cases and maximum vertical displacement with case 2 and 6 which have ±45 degree is smaller than other cases’ displacements.

Between the RC and SC structures, the connection method, such as baseplate type(mechanical splice) & noncontact lap splices, was suggested in KEPIC SNG. In previous research, baseplate type using #14bar were developed and their structural integrity was confirmed by the actual bending test. However, the structural integrity of noncontact lap splices using #14bar has not been yet confirmed through experiment. In this study, load-displacement curve of noncontact lap splices FEM model is compared with baseplate type analytical results. This research suggests the possibility of the noncontact lap splice for connection design in case of #14 dowel bar of RC Structure.

The smart strand built-in with core wire were fabricated and submitted to test. The results showed that the application of smart strand at pier structures.

Steel pipe pile, which is used for the base of structures, need the reinforcing head method to prove enough dynamic performance. Currently there are various reinforcing head methods are used, but most of them have problems of structural complications and heavy charges. Thus, this study is to develop a reinforcing head method for steel pipe piles using hook type bending reinforcement, which can fix piles using nuts, and experimentally prove structural performances.

This paper presents the optimized design of Coal Silo structure using 2,400MPa PS strand and their economic benefits. Original structural design on the Coal Silo structure using 1,860MPa PS strand was reviewed in order to compare the values from the design with the optimization results.

In this study, We evaluated the impact resistance of structural member using high performance fiber reinforced cementitous composite according to compressive strength. As the compressive strength of structural member using HPFRCC increased, the deflection of the structural member decreased. The highest resistance of deflection occurred at 180 MPa HPFRCC.

This paper describes the structural performance of coupling beam with diagonal steel tube for reinforcement detail simplification of RC coupling beam. Two coupling beams were made and tested to compare the structural performance of coupling beam with diagonal steel bar and that with diagonal steel tube.

It is difficult to predict scabbing limit thickness of fiber reinforced concrete, because existing formulas are not consider fiber reinforcing effect. So, In this study, obtaining the fiber reinforced factor and factors are applied to Modified NDRC formula. As results, it was possible to make accurate prediction for scabbing limit thickness of fiber reinforced concrete.

Space took place between two superstructures of which two bridges are adjacent each other. The cause of space between superstructures turn out to be due to several reason such as stratum composition by various ground condition, ground stability after completion of structure, ground stress bulb double, etc.

In this study, an Wireless Data Transmission Module for Large Spatial Structures has been investigated. An Wireless Data Transmission Mobule was designed with a Zigbee-based wireless communication function and a low-power, a variety of external interface. This was designed using RadioPulse Inc's MG2470-chip with a Zigbee-based wireless communication function, and Power Circuit was designed using Battery. The MG2470-chip is a true 2.4GHz system-on-chip (SoC) designed for low-power, low-cost applications based on the industry standards such as IEEE802.15.4 and RF4CE. The MG2470 involves 8-bit 8051 MCU with internal 64-KB flash memory and 6-KB SRAM. Accordingly, it is possible to development of an optimal firmware.

The purpose of this study is to present a suitable maintenance guide or plan for future small scale vulnerable facilities by analyzing the investigation data collected through the safety inspection. For this, we examined about 3,301 buildings. From a number of defects, damages associated with the safety and durability of building were preferentially analyzed.