Traditional methods for demolition of concrete structures and rocks are jackhammer and explosives methods. However, these traditional methods may not adequate specially for urban areas and historical places. Accordingly, an use of soundless chemical demolition agent (SCDA) increases in those areas. SCDA is similar to portland cement and lime is a key ingredient. In this study, expansive pressure from the selected SCDA were measured using outer pipe measuring technique and crack length due to the SCDA were simulated using obtained test data.
The purpose of this experimental study is to investigate the influence of chemical resistance of concrete using KOH and Non-sintered binder. As a result, concrete using KOH and Non-sintered binder was confirmed to be superior than ordinary of concrete chemical resistance.
Recently, scaling of pavement concrete is becoming problem by excessive use of deicer. The current study measured durability of concrete not considering multi-deterioration using design and construction mixing used general concrete pavement.
The remaining service life (RSL) of the concrete structures built in the past has become a social issue with the concerns of the sustainable construction. In the previous studies, some simple methods for estimation of the RSL of the concrete structures were proposed. However, most of the existing studies on the RSL evaluation method have focussed on the investigation of the single deteriorating factor. In this study, the combination effect of various factors related with durability performances of the concrete structure, such as concrete carbonation and chloride penetration were considered by utilizing the fuzzy and reliability theory.
The durability of Latex modified concrete(LMC) is increased when compared with conventional pavement concrete. But LMC have a several problems. In odrer to improve the problem of LMC, Remicon latex modified concrete(Remicon LMC) was developed. In this study, the durability of Remcion LMC containing extra admixture was compared with latex ratio. From the results, when latex and admixture was mixed in concrete, the micro-pores are decreased. And, the durability of Remicon LMC is increased comparing to conventional concrete.
Recently, there are comprehensive efforts to reduce greenhouse gas emissions in a global community. CO2 reduction effect can be expected when admixture contents improved with the use of limestone power, instead of clinker which is a main factor of CO2 gases. In this study, elapsed time change of concrete using limestone power was evaluated.
In this research, we evaluate the workability of 100 MPa concrete for CFT column thru Batch plant test. Also, we evaluate the fire resistance performance of steel composite column.
In this study, as well as natural disasters, disasters caused by human factors, even disasters can consider integrated regional risk assessment aims at the development of techniques. Facility of one of its elements a disaster risk factor deriving method are described.
The purpose of this study is to evaluate the collapse probability of structural member in building. Probability of material strength and live load were collected. By evaluating the probability distribution for design strength and required strength, the probability on the collapse of a column were evaluated.
The purpose of this study is to estimate the weighting factor on inspection categories for risk assessment of buildings. For the purpose, survey of practitioners and experts conducted. By A.H.P.(Analytic hierarchy process), relative weighting factor in inspection categories were estimated.
This paper indicates seismic performance of wing walls using Engineered Cement Composite (ECC). The variable of specimens is 2 side connect and 3 side connect in RC frame. The specimens is tested cyclic lateral loads by actuator. The test results show that seismic performance of 2 side connected wing walls improved.
The purpose of this study is to use organisms or micro-organism functions for eco-friendly water-purification according to concentration in porous concrete using EM, utilizing bioremediation.
In recent years, High-Rise buildings are increased. For this reason, using large size member of framework is inevitable. High hydration heat which is caused by large size member of framework makes structure to take serious risk of durability. To solve this problem, a variety of researches are proceeding. Recently, several studies about decreasing cement hydration heat by using Urea are reported. In this study, thermal performance evaluation experiment conducted on cementious materials using urea. In addition, hydration heat is predicted through theoretic consideration and conducted comparative analysis of difference between the results from experiment and theoretic prediction. Results of experiment showed hydration heat was decreased by increasing amount of urea addiction. Through a comparative analysis, error range is included in plus or minus five percent in the dissolution test and thermal performance evaluation test of cement mortar.
Mathematical models of shrinkage and creep are based on the experimental evidences obtained from the ideal laboratory environment. In case of the age-dependent behavior of RC beam, the shrinkage strain may not be uniform through the depth of beam whereas it has been usually assumed to be uniform through the beam depth. This paper addresses the assumption of uniform shrink\age strain through the beam depth and flexural creep that has been observed from the recent test program.
In this study, natural fine aggregates(NFA) and recycled fine aggregates(RFA) was applying in the lightweight foamed concrete. To replacement of OPC, high volume blast furnace slag was used and incineration ash and recycled aggregates powder were used as alrali activator, Fundamental performances of lightweight famed concrete has been tested. Results showed that as the increase of foam conduction ratio, the strength and the density has been decreased
In this study, strain distribution of the beam end and the end of horizontal stiffener of high-strength steel beam-to-column connections was analyzed by finite element methods. According to the FEM results, applied stiffener method showed that it is available to relieve the strain of maximum stress point of beam member
In this study, bond performance of grouted joint with high performance cement grout was verified. The grout which the compressive strength of grout was over 120MPa. was applied for wind turbine tower connections. From the results, the connection joint using high performance grout has sufficient bond strength.
Underground material and to secure any other appropriate waterproofing method for improving the workability experiments on non-woven fabric weight is selected. As a result, the appropriate non-woven fabric weight of 140 g/㎡ was confirmed.
Thermal spray coatings and organic coatings are often individually used in corrosion protection of steel structures. Duplex coating systems of thermally sprayed metal coating combination with organic coating represent a new generic type of coatings on offshore steel structures under the highly corrosive environments. In this study, weathering test were carried out on four types of duplex coated specimens; thermally sprayed metals of zinc, zinc-aluminum alloy, aluminum and aluminum-magnesium alloy in combination with painting of acrylic urethane. From the test results, weathering performance of the duplex coating systems were evaluated.