Hasil Pencarian  ::  Simpan CSV :: Kembali

Abstrak :
One method of increasing the durability of cylindrical concrete columns in aggressive surroundings is by providing a PVC skin around the columns. Beside protection added mechanical benefits have been investigated in this study. Results of this endeavor are reported in this paper. One hundred and fourteen specimens were prepared utilizing prepacked aggregate concrete (PA-Concrete), Consisting of andesite coarse aggregates and cement grout with 30% fly ash as partial cement replacement. Cylindrical specimens with varying length over diameter ratios (LID) and ages have been tested for their strength and ductilities. Results have shown the prevalence of beneficial composite behavior in PVC-confined specimens. Strength increases of 30% to 50% above those of unconfined specimens have been observed. Displacement ductilities lA > 7 have been derived, implying an increase of more than 8 times of those of unconfined specimens. Strains ductilities /l. > 2.4 and residual strength ratios R> 0.52Rp have been observed. Results indicate that strength increase with increasing ages while ductilities decrease with increasing un values. Toward the end of this paper, attempt is made to explain the mechanics of confinement in generating high load capacities of PVC protected columns.

Abstrak :
For centuries humankind has wondered at the instability of earth material, especially clays; one day they are dry and hard, and the next wet and soft. The result are usually excessive deflections and diffrential movements resulting in damage to foundation systems structural elements and architectural features. Foundation materials that exhibit volume change from change in soil moisture are referred to as expansive or swelling clay soils. Expansive soils many parts of the United States a significant hazard to foundations for light buildings. Swelling clays derived from residual soils can exert uplift pressures of as much as 5.500 psf to 15,000 psf. In the United States alone the damage caused by the shrinking and swelling soils amounts to about 9 billion dollars per year, which is greater than the combined damages from natural disasters such as floods, hurricanes, earthquakes and tornados.South Sumatra local Government is planning to build a new International and Modem Trading Port including Industrial and Ware Housing Estate at Tanjung Api-Api area. Most of soils around Tanjung Api-Api area are expansive soils, so the objective of this study to analize and obtain suitable foundation on unsaturated expansive soil, that can be implemented in Tanjung Api-Api area. From the result ofOedometer test, it can be concleded that the swelling potential value is about 15 percent, and the soil uplift pressure is about 2,0000 psf.

Abstrak :
The construction of the retaining wall should be base on stability calculation and safety factor, because any error in the construction process can have fatal consequences in property damages and the lost of life. The case of retaining wall at Lapangan Parkir Dermaga Pengumbuk is the damage of its retaining wall, which can be observe by the movement of the retaining wall in horizontal direction and the cracks on the retaining wall. Analysis indicate that the retaining wall failure on this case is due to shear instability, and the creep also contributed to the construction movement on the location. This paper contains the analysis of the problems on the retaining to have an effective and efficient alternative problem solutions.

Abstrak :
Overlaid asphalt onto concrete pavement is another alternative than regrooving; it creates a composite layer of concrete-asphalt. Monolithic concrete-asphalts depend on bonding at its interface and affected by direction, space and depth of grooving, quantity and may type of tack coat used. This research aimed to know the effect of grooving direction to shear resistance of the interface on concrete-asphalt composite layer. Three types of grooving: transversal, angle of 45° and longitudinal, used. Emulsied asphalt of CRS-I and cut back asphalt of RC-70 by quantity of 0, 2 l/m2and 0, 6 l/m2 applied as a tack coat. As the results, it is known that shear resistance of the interface on concrete-asphalt composite layer affected not only on grooving direction but also quantity of tack coat and normal force applied. For concrete-asphalt composite layer, the highest shear resistance given by transversal grooving direction and 45° angle of grooving direction is better than longitudinal grooving. For all grooving direction, CRS-I emulsified asphalt has a higher shear resistance than RC-70 cut back asphalt and changing of adhesiveness of RC-70 caused of normal force is more susceptible than CRS-I.