Time Dependent Properties of Concrete: A State of the Art Review

This work summarizes the prediction models for creep strain that taken place in concrete under compression as well as under tension and shear. In literature, many researchers have carried out experimental studies on creep, RILEM has gathered these experimental results within a computerized data bank. This work briefly reviews the most widely used models and can predict observations up to 5000 days assessed by ACI209R-1992 Model, B3 Model, CEB C99 Model, GL 2000 Model, BS 8110 (1985), and AS3600 (1988). Since creep is one of the most important time-dependent properties of concrete as it increases cracking and harmfully distresses the function, durability, and structural appearances. The objective of this work is to understand the behavior of concrete when creep strain takes place at different ages by incorporating spreadsheets which simplify the calculations for engineers when estimating the creep strain for the design purpose. Based on the RILEM data bank, most of the studies confirm that the GL2000 Model is the closest to the experimental results.

Product Design for Reuse of Waste Construction Wood——Teapot Tray Design Practices

By using waste construction wood as the main raw material, the design practice is based on increasing the storage function of the teapot tray. In the design of the product, we strive to show the unique texture of the waste construction wood. Structural design is based on tenon-and-mortise structure, convenient assembly and disassembly of products as design principles, easy replacement of parts and continuation of product life as design purpose, and teapot tray design through product modular design ideas. Modeling design combined with traditional cultural concepts to “turn waste into treasure.”

Project

The research aims to enhance student’s awareness about the environment through project-based learning. In learning process students are expected to solve school environment problems of waste management . The study was conducted on the students of grade X, in one of the Vocational Schools in Bogor for 3 meetings. Students are given worksheet as a guide for designing waste treatment projects. The researcher used six stages according to Doppelt (2004), namely: 1) Design purpose; 2) Inquiry field; 3) Solution; 4) Choosing the preferred solutions; 5) Operation step; 6) Evaluation. Indicators of awareness for the environment used Dunlap and Liere (2000) instruments, including: 1) fragility of natural balance in the school environment; 2) ecological crisis in the school environment; 3) the reality of limited natural resources in the school environment; 4) Anti-anthropocentrism of students in the school environment; 5) rejection of exceptionalism.The results showed an increase of awareness towards the school environment with N-gain score category is medium (N gain= 0,41). Students also appreciate and maintain the school environment.

Design and Experiment of Symmetrical Shape Deployable Arc Profiling Mechanism Based on Composite Multi-Cam Structure

At present, there are few reports on the profiling mechanism that can achieve surface envelope profiling along the surface of a shaft whose radius is constantly changing. Existing profiling mechanisms cannot achieve this function. To this end, a novel deployable arc profiling mechanism is presented in this paper. The mechanism can realize centering deployment along the shaft with a changing radius. The radius of the deployable arc can be adapted to the continuous change of shaft radius, and its surface can always maintain the arc shape for surface envelope profiling. The mechanism is mainly composed of compound cams. Each cam contains multiple grooves, and each groove connects to an arc support linkage. The arc support linkage is controlled by the compound motion of cams in different layers. The pitch curve of each groove is designed by applying the method of relative motion and inverse solution and obtained various parameter equations of the mechanism. The feasibility of this mechanism is verified by analysis, experiment, and application test. The results show that the proposed deployable arc profiling mechanism can achieve the design purpose and the profiling accuracy is kept above 96.425%.

Does the Universe Suggest Design, Purpose, Goodness, or Concern?

This chapter tackles the question of whether or not the natural world presents us with a picture empty of purpose or good or evil or concern. No empirical evidence can entirely refute the claim that random fluctuation is the complete truth about the origin of all things, but it follows that this is not a scientific claim. Therefore it is a question of forming a reasonable judgement. It appears that the natural world has a depth and richness that exceeds what would be necessary for thinking brains to come to be realized in it. Also, notwithstanding the pain of the world, it is a project that merits our engagement and commitment, and occasionally the transcendent breaks in. We are not competent to make an overall judgement, but we can join in with the creative process of the world and find our role.