土木環境工学ジャーナル

Piles act as a settlement reducer in case of connected piled-raft foundation and hence decrease the settlements of the raft. The design concept of the connected piled-raft foundations is to lessen the number of piles and utilize the bearing capacity entirely. Due to significant straining actions at the pile head-raft connection, an alternative technique is proposed to disconnect the piles from the raft. A Granular layer (cushion) beneath the raft is incorporated. The disconnection has a beneficial effect on reducing axial load compared to connected piles. For small piled rafts, non-connected piled rafts show less stiffness than connected piled rafts, and the soil is highly stressed and shows greater raft settlement. In the case of the large piled raft, non-connected piled rafts show greater settlement efficiency. However, as compared to the non-connected piled raft, the connected piled rafts show a significant reduction in raft settlement as pile spacing increases. The results show that the load transfer mechanism in a nonconnected piled raft is mainly governed by the thickness and stiffness of the cushion layer and by the stiffness of the subsoil.

In recent years, there has been an increasing interest in the thermal properties of building materials to increase comfortability, low energy consumption, and sustainability when used the Expanded Polystyrene Waste (EPSw) as a filler substance. Using this non-biodegradable waste in cement mortar represents a solution to minimize 2 its negative impact on our environment as well as to reduce the CO₂ emission due to cement manufacturing. Five groups of cement mortar containing chopped EPSw (20, 30, 40, 50, and 60 volume percentage) in addition to the reference mix were poured to investigate the density, thermal conductivity, water absorption, compressive strength, and flexural strength. The distribution of the non-homogeneous ingredients was controlled by using a superplasticizer admixture and using chopped EPSw of 1 mm maximum size particles. Results show a high reduction in the thermal conductivity (70.5%) of the mortar containing 60% EPSw compared with the control mix. However, other mechanical properties had acceptable values for many building applications, even for the masonry products of compressive strength of 5 MPa.

The civil war in Somalia that erupted in 1990 has destroyed totally the major water resources infrastructures including boreholes. Hence, The main purpose of this research was to analyze sustainability and management of the water supply systems (Tadamun/Hawa tako, Tadamun/ If & Akhiro, Dudublaha, Maskaxey, and Wanjel) managed by water users committee implemented in Afgoi district, Somalia; In addition, this research also studied the water supply systems and its sustainability. This reseach focuses primarily on the assessments carried out in the field, observations, household survey, and water tests; Results shows that all the studied schemes are financially and technically sustainable and able to delivered good quality of water to the users. Though, the water schemes are self-reliant, regularly provide major technical assistance. Hence all of the water supply system seems to be smoothly operating without financial, technical or institution problems with in water supply system and the community. Thus, it can be concluded that five water supply systems are providing quality drinking water to the people.

In this article, you will learn about the rapid development and maintenance of traditional chaykhana in Central Asia, as well as the new approaches to household and service facilities. And an architectural solution is given, taking into account modern, national and climatic, functional and traditional factors.

Self-Consolidating Concrete (SCC) is a special concrete which is highly flowable, non-segregating and by its own weight spread into place, completely fill the formwork even in the presence of dense reinforcement without any compaction. This research was implemented to develop and to determine the effect of FA on fresh and hardened properties of self-consolidating concrete. Laboratory test was carried out to investigate the properties of SCC. Five composition of design mix at 0%, 15%, 30%, 45% and 60% fly ash were prepared and tested. The performance of the fresh SCC mixes was determined by testing the filling ability and passing ability through slump flow and slump T50 test, L-box and v funnel test. Standard concrete cylinders were casted comprising of five mixes, cured and tested for analyzing the compressive and split tensile strength behavior of SCC. The results indicate that as the amount of FA increase, the flow and passing ability is decreased continuously. However up to 45% of FA by weight of cement will fall within the limits define by technical specification for SCC and have good passing and flowability. Early age strength (7 days) decreased as the percentage of FA increased while long term the strength (28 and 56) is increased first up to 45% substitution of FA and then decreased gradually.