This paper summarizes the state of art on concrete pavement design procedures. First, on jointed concrete pavements, design procedures in both Japan and foreign countries are explained in roads, airports, ports, separately. Second, design procedures of continuously reinforced concrete pavement, prestressed concrete pavement, roller compacted concrete pavement, steel fiber reinforced concrete pavement and block pavement are described. Finally, new structural design procedure specified by the Japan Society of Civil Engineers, which is based on the pavement serviceability, is summarized briefly.

View full abstract

Many studies on the rheology of fresh concrete have been carried out recently. However, it is difficult to apply the almost rheological tests to the evaluating method for fresh concretes directly because of its complicated properties due to the non-homogeneity. Though the slump test has being used in construction site as a workability test or consistency test, the theoretical and mechanical meanings of slump test are not recognized, and this shortage of understanding is considered to be one of the obstruction for establishing the reasonable evaluation system for the quality of fresh concrete. In this paper, some studies investigating the mechanical meaning of the consistency tests and the rheological meaning of the material properties measured by these tests are introduced, and the problems and the prospects in the evaluation system of fresh concrete are discussed.

View full abstract

Recent remarkable changes in construction environment are demanding improved technology for production of high performance concrete with low heat, far greater workability and high strength. With these points as background, belite rich cements which were first developed as a low heat cement, are being applied to high strength and highly flowable concrete and/or low heat and high strength concrete with a design strength F_c in the range of 60 to 80 N/mm2, and their effectiveness is being recognized. This paper outlines the current status of belite rich cement in terms of its type, and discusses its action mechanisms for fluidity and strength development from the viewpoints of selectively nonuniform absorption of AE and high-range water reducing agent and the hydration reaction of the cement compounds, respectively. Finally, the typical properties of concrete made with belite rich cement are introduced and compared with ordinary Portland cement.

View full abstract

[in Japanese]

View full abstract