In current research, it was attempted a preliminary design and evaluation of non-uniform ultra high-strength concrete (UHSC) truss members. UHSC used here has the compressive strength of 180 MPa, the tensile strength of 8 to 20 MPa, and the tensile strain after cracks up to 2%. By the three-dimensional finite element stress analysis as well as strut-tie approach on concrete solid beams, the non-uniform truss shape of UHSC truss was designed with the architectural esthetic concept. In a series of examples, to compare with conventional concrete members, the proposed UHSC truss members have advantages in capabilities of the slender design with minimum weight with high performances under transverse loadings as well as the aesthetically non-uniform design for spatial structures.

콘크리트 깊은 보의 전단강도 산정을 위해 현행 미국콘크리트학회(ACI) 및 캐나다표준규격협회(CSA), 유럽콘크리트위원회(CEB-FIP)의 설계기준은 스트럿-타이 모델을 이용할 것을 제안하고 있지만 설계의 품질이 설계자가 구성한 트러스 모델 적합성에 크게 좌우된다는 특징을 가지고 있다. 따라서 본 논문에서는 내부 트러스 모델에 따른 현행 ACI, CSA 및 CEB-FIP의 콘크리트 깊은 보 설계기준의 타당성을 홍성걸 등에 의해 제안된 콘크리트 소성학에 근거한 전단강도식의 예측치와 비교함으로써 평가한다. 비교 결과 ACI, CSA 및 CEB-FIP의 스트럿-타이 모델에 의해 설계된 깊은 보의 경우 내부트러스 모델이 전단강도 예측에 중요한 영향을 미치는 것으로 나타났으며 CEB-FIP의 경우 가장 높은 스트럿 강도 예측치를 보였다.

This research was an attempt to design a new structural concept of non-uniform reinforced and super concrete truss members applying by super concrete which has the compressive strength of 80-200MPa, the tensile strength of 8-20MPa, and the tensile strain of 1.0-5.0%. The super concrete truss members were designed by the Strut-Tie approach as well as aesthetic design concept. The structural performance of designed superconcrete truss was evaluated with the conventional reinforced concrete members.

In this study, to examine the application of strut of high strength concrete, an parameter study was performed. High strength concrete has high capacity for the strut member, especially 80MPa concrete strut has equal quality to 40MPa concrete strut with FRP. Also it is insignificant that the difference of member force between variation in boundary condition on the strut of PSC Box Girder.

In this study, to examine the application of strut of high strength concrete, an experimental study and analysis was performed. High strength concrete has high capacity for the strut member, especially 80MPa concrete strut has equal quality to 40MPa concrete strut with FRP.

The current American Concrete Institute (ACI), Canadian Standard Associate (CSA) and CEB-FIP code suggest that deep beams should be designed using the strut-and-tie model approach. This paper investigates the validity of the current ACI, CSA and CEB-FIP code provisions on the shear strength of simply supported reinforced concrete deep beams by comparing them with the shear strength equations proposed by Hong et al. (2002) The comparison shows that all of these code provisions provide reasonable estimates on the shear strength of concrete deep beam members and the ACI and CEB-FIP codes results in similar estimates while the CSA code relatively underestimate the strength.