Daniel Tjandra

IMPROVING MARINE CLAYS WITH ELECTROKINETICS METHOD

This paper reports the results of investigations carried out on the effect of varying curing age and water/cement ratio on the modulus of elasticity and modulus of deformability of laterized concrete. The test specimens were made with sieved samples of selected grain size ranges of laterite used as fine aggregates to replace sand in normal concrete. Batching was by weight. Three mix ratios of (1:11⁄2:3), (1:2:4) and (1:3:6) were used. Water/cement ratio of 0.5, 0.6, 0.7 and 0.75 were used for each of the mix ratios. The specimens were tested at curing ages of seven to 28 days. The results showed that there was a corresponding increase in both modulus of elasticity and modulus of deformability of laterized concrete due to increase in curing ages. The mix proportion, compressive strength and water/cement ratio were found to have significant effects on both modulus of elasticity and modulus of deformability of laterized concrete.Advanced Traffic Control Systems (ATCS) have been recognised as one of the most direct methods for relieving urban traffic congestion. However, the applications of the systems in large cities in developing countries are unique because road networks in these cities face more severe transportation problems than those in developed countries. Furthermore, some of signalised intersections lie close, but others far from adjacent intersections. The aim of this paper is to evaluate the performance of ATCS at intersections with far distance to adjacent intersections and to recommend how to improve traffic performance with given constraints of severe transportation problems. Road network in Bandung, Indonesia was used as a case study. Microscopic traffic simulation was conducted to evaluate the performance of ATCS. It is shown that on average, traffic performance measures under Fixed Time traffic control system were similar or better than those under ATCS. In conclusion, the application of ATCS at intersections far from adjacent intersections is not effective.The high water content in marine clays could loosen the bond of soil particles, resulting in low bearing capacity and high compressibility of the soil. Excessive settlements could happened to the structures built on it. An electrokinetic process was attempted to reduce the high water content of the marine clay. An experimental study was conducted to evaluate the effect of electrokinetic on marine clay improvement. This study focused on the use of electrokinetic to enhance the soil bearing capacity of marine clay by improving index properties of the marine clay. The result of this research was obtained by doing several analyses on water content, pH value, and soil particles of soil sample located between cathode and anode. Based on the results from laboratory testing, it can be concluded that electrokinetic process decreased the water content and pH value of soil surrounding the anode. Also, soil particles surrounding the anode became in close proximity. This indicated that as it became closer to the anode, soil became denser.The desired accuracy level of an estimate heavily relies on the availability of data and information at the time of preparing the estimate. However, an estimate often must be made when data and information are not complete. At earlier stages of project implementation at which data and information are minimal, a client is often required to prepare a cost estimate. This paper discusses the capacity factor-based cost models for buildings with total areas serving as the proxy of capacity. A total of four cost models for different building functions are presented in this paper. Based on the models, most building functions with the exception of housings, exhibit decreasing return to scale, meaning that the unit measure of cost expressed by cost per square meter declines as the size of capacity increases. The cost models are then applied to estimate the development unit cost for different demographical unit measures.

PENGARUH ELEKTROKINETIK TERHADAP DAYA DUKUNG PONDASI TIANG DI LEMPUNG MARINA

The essence of building design process and management for building sustainability in the creation and maintenance of a qualitative architectural product is investigated in this paper. The design process, concept of building sustainability and particularly the quality of the built environment are discussed. Akure, a state capital in Nigeria was used as a case study. The principles and indicators for sustainability of buildings and its implications on the quality of the environment are examined in details. Survey findings include the views of the professionals on the clients, perception on the design process as well as management of projects, and the implications on the quality of the ensuring products and the city’s environment. The data were factor analyzed using varimax rotation criterion (with Kaiser Normalization). The results revealed that five factors were effective, with one of them exhibiting the greatest variability and individual differences. The variables that loaded on this factor were really the aspects of the process and management relating to the clients. The findings also revealed the professionals’ wrong attitude towards design process as shown with a very high degree of variability in the study. The paper concludes by recommending the enactment and enforcement of relevant policies with adequate education of the people and the involvement of all the stakeholders in the management of building projects and environmental programmes for the realization of a qualitative architectural product.