ASIAN JOURNAL OF CIVIL ENGINEERING (BUILDING AND HOUSING)
Year:2001 | Volume:2 | Issue:2|Papers Count:6

To increase the amount of information concerning bamboo which could be used either alone or as reinforcement in different types of matrices such as soil and cement composites, several successful research programs have been carried out since 1979at PUC-Rio and in Brazil. This paper presents some of the recent studies of the microstructure of bamboo as a functionally gradient material, which led to the establishment of its composite behaviour through the rule of mix. A concise summary about bamboo reinforced concrete beams, permanent shutter concrete slabs and columns is discussed. Finally, some recommendations for future studies are proposed with the hope that the newly developed material in future could contribute on a large scale to a sustainable development without destroying our globe.

The length of the steady Gradually Varied Flow (G.V.F) profile in a circular gravity pipe section is computed using the Graphical Integration Method. The equations used for the solution are: a) the dynamic equation of Gradually Varied Flow in a prismatic channels, b) the hydraulic exponents M and N equation derived by Chow [2], and c) the Varied hydraulic exponents M (y/do) and N(y/do) equation modified by Zaghloul [15]. The results of the calculated G.V.F profile length using the modified hydraulic exponents M(y/do) and N(y/do) equation are closer to the G.V.F length calculated based on the exact formulation of the G.V.F dynamic equation. The percentage difference ranges from 0.67% to 8.72% for various bed slopes and G.V.F depth limits. The calculated G.V.F profile length using the Chow hydraulic exponents M and N resulted in wider values with percentage difference ranges from 0.16 to 25.59%. Hence, a remarkable improvement of the computation of G.V.F profile is achieved using the modified M(y/do) and N(y/do) hydraulic exponents.The unsteady Gradually Varied Flow wave propagation in circular gravity pipe section is simulated using the Explicit Method. The Extended Transport block (EXTRAN) of the latest Storm Water Management Model (PCSWMM2000) was used to route the wave through a circular gravity pipe section. The resulting routed hydrographs by the Explicit Method and the EXTRAN Block of the PCSWMM 2000, provided similar flow peak and lag time in both cases.A computer package was developed for the Steady G.V.F length calculation for gravity pipes using the Microsoft Excel spreadsheet. The results are plotted using the Excel graphics capabilities.A second computer package using Microsoft Excel was developed for the Unsteady G.V.F simulation based on the Explicit Method. The routed hydrographs arc plotted by the Excel graphics capabilities.The Excel packages for the Steady and Unsteady G.V.F are user friendly and are posted on the Internet Website location http://briefcase.yahoo.com/civil engineering2001.ARead me File is provided for each Excel package and is used as a users guide.

Non-linear finite element analysis is performed for a total number of 40 semi-rigid connections, and M-ф diagrams are obtained. Each diagram is represented by a multi-linear relationship through 25 points.A neural networks is trained for the prediction of M-ф diagrams for the considered type of connections. The results obtained by the trained back propagation neural network are found to be quite satisfactory compared to those of the finite element analyses.

This paper presents a method of analysis for evaluating the softening behavior of RC members. In order to obtain mesh objective results, a non-local fiber element model is introduced. The resisting force of each section, in the non-local fiber element model, is calculated using a proposed differential hysteretic model, which is especially developed for modeling softening behavior under cyclic loading. The section hysteretic response is determined using microphone constitutive model for concrete and bi-linear elasto-plastic model for reinforcements. The calculated hysteretic behavior of sections is employed to scale the parameters of the differential hysteretic model. The proposed method is verified by the available experimental results. Close agreements between the numerical and experimental results are obtained. The method provides insight to the procedure of flexural localization. Also, due to computational efficiency of the method, it is possible to extend its use for analyzing RC frames with softening members.

The influence of detailing on the behavior of steel fibber reinforced concrete (SFRC) opening corners is reported. Mixed rather than one, aspect ratio of crimped-type steel fibers was used in the concrete. The variable investigated, was the amount of splay steel in the corner. The inclusion of splay steel stiffens the joint and substantially increases its effectively used in the currently recommended splay steel content could be effectively used in the corner hence the failure occurs due to formation of a hinge in one of the members framing into corner rather than a diagonal tension failure at the corner itself, as obtained in non-fiber concrete opening corners. On the basis of the results of this and another investigation on SFRC opening corners, it can be concluded that splay steel contents in excess of the hitherto recommended 50% of the main steel percentage, can be efficiently used in SFRC opening corners.

Improper tender selection could result in several drawbacks during construction which usually are reflected as cost over-runs, delays and poor quality. This is occurring in many public construction projects in Kuwait, which are managed by different ministries and authorities such as the Ministry of Public Works (MPW) and National Authority for Housing Care (NAHC). As an attempt to escape such drawbacks due to the current selection process of one major public agency, the MPW, this research suggests a new systematic approach for tender selection and ranking that would optimize client objectives. This system is a Knowledge-Based Expert System (KBES) that utilizes available expertise of decision-makers for tender evaluation, contractor's pre-qualifications, current capabilities and submitted plans. The KBES is flexible enough to consider the varying project conditions and objectives with contractor's qualifications. The system is specially designed to suit the construction environment in Kuwait and similar environments.