In construction field, a time completion and an adherence to budget are two factors that mainly influence the successful of the projects. The adherence to the budget can be achieved when the estimated budget is closed to the actual cost. For the owners, cost estimation is necessary as a guidance in determining the amount of investment. Therefore, it is very important to know the estimation of the project cost by using the limited data before the detailed plans and specifications of the project are identified. However, in the case of bridge substructure preliminary cost estimation, there is a lack information about material quantity estimation models due to the difficulties of soil characteristic and hydrological conditions. Hence, this research aims to develop the estimation of material quantity models of the abutment and caisson of bridge, with the Presetressed Concrete I-Girder (PCI Girder) superstructure located in Sleman district, Yogyakarta province, Indonesia. The database used for developing model was obtained by conducting sub-structure structural analysis of 15 abutments and 45 caissons. The bridges have a various span length, abutment height, and caisson depth. Material quantity estimation models were analysed by the multiple regression analysis methods. The span length and the abutment height are determined as independent variables to predict the concrete volume, the reinforcing steel weight, the caisson concrete volume, the cyclops concrete volume and the caisson reinforcing steel weight. This research proposed 11 equation models to estimate the concrete volume and reinforcing steel weight of abutment and caisson.
This paper focuses on the effect of polypropylene (PP) fibers on the mechanical properties and thermal conductivity of fly ash-based geopolymer foams. Class C Fly ash (FA) was used as a binder material. A mixture of sodium silicate (SS) and sodium hydroxide (SH) was used as an alkaline activator of the geopolymer binder. The foams were prepared mechanically by mixing the foaming agent with distilled water at high pressure. The foams were added to the geopolymer admixture with volumes of 40% and 60%. A small dosage of PP was varied from 0%, 0.25%, and 0.50% by weight of fly ash (FA). The result showed that the strength of foamed geopolymer rises as the PP fiber content increases. The PP fiber was proven to increase the tensile strength of foamed geopolymer due to the ability of PP fiber to connect the crack and improve the tensile strength. The PP fiber amount in this study significantly affects the thermal conductivity of foamed geopolymer. However, the thermal conductivity in this study has the same properties as lightweight concrete and a little higher than gypsum board.
An experimental and theoretical are presented to calculate the load capacity of shear single connection (SSC) and shear double connection (SDC) without void filled material. The model presents an extension of the Johansen theory for bamboo connection type, also known as the European Yield Model (EYM). The bamboo of Gigantchloa atroviolacea of the most popular as non-wood has been used as a construction material in some region of Indonesia. The uniqueness bamboo is bamboo non-homogen material, sectional shape non-prismatic, the straighthness stems not same, on the culms guiler node and a cross-section in hollow. The diameter of Gigantochloa atroviolacea bamboo used in this study is ranged from 70 to 90 mm. The diameter of bolt is 12.7 mm. The connection strength can be determined with theoretical and eksperimental. Application theory of the European Yield Model could be developed into theory of connection laterally strength of bamboo without void filler material. Factors that affected of connection laterally strength is bamboo thickness, bolt diameter and spesific gravity. The equation four of connection strength base on European Yield model can calculated of according to yield model of accurred. The connection strength is specified from the value smallest of the equation four of connection yield models.
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