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From the analysis of the production process of molded pulp packaging, it can be seen that one of the residues generated in the molding is “pulp”. When this waste cannot be reincorporated into the production line, is recovered by centrifugation in the effluent treatment system. With the intention of recycling this residue it was investigated the feasibility of their use in the manufacture of concrete blocks or panels lightened studying possible ways to use the material, either in the wet state (form is discharged from the process) or dry (dried in a controlled environment), analyzing the advantages and disadvantages of each alternative. For practical purposes, various dosages were proposed to maintain constant the amount of residue and varying the amounts and proportions of water and cement. Test specimens were made with various amounts of cement per m 3 of concrete. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a systematic approach for the experimental testing and analysis of the early-age thermo-mechanical behaviour of large prismatic high-performance concrete specimens under restrained autogenous shrinkage and realistic temperature conditions. The loading system can apply a partial degree of restraint in order to enable the characterisation of high-performance concrete specimens without premature termination of the test in case of significant restrained shrinkage. The instrumentation system can measure the strains and other parameters from the setting time with high accuracy and reliability. The analysis method takes into account the temperature effects on the measured properties and provides equations to determine the time-evolution of shrinkage, thermal expansion, stiffness and creep of the concrete. Results from the testing of 200×200×1000 mm specimens made with a 0.34 water–cement ratio concrete are presented, analysed and discussed in the paper to demonstrate the application of the proposed approach. [Copyright &y& Elsevier]

Abstract: To solve the problem of the waste generated by the natural stone industry, several technical solutions consider the incorporation of this type of waste in other industrial activities as a by-product. This paper presents an overview of current solutions and the results of a research project where natural stone slurry is used to replace fine aggregates in concrete mixtures. The concrete mechanical properties are presented and the technical viability of this new construction material is illustrated. [Copyright &y& Elsevier]

In the current paper, the effect of tensile softening parameters, the tensile strength σt and the initial slope k1 of the stress-crack width curve, on the structural size-effect law in bending of concrete are studied by a bending model. The model results show that the size-effect law in bending strength normally presented by flexural strength and beam height diagram (σf-logH) is strongly dependent on σt and k1. With increase of beam height, the general size-effect law in bending can be characterised as a fast reduction stage followed by a stable decreasing stage and finally converged to the tensile strength of concrete. With increasing tensile strength, the σf-logH curve goes up and the value of dσf/dlogH gradually increases. In the meantime, for a given beam height, bending strength increases with increase of k1. The model predictions are compared with experimental results. Good agreement between model predictions and experiments has been obtained. [ABSTRACT FROM AUTHOR]

Field lateral load tests were conducted on two single 1.5 m diameter large bored piles in Hong Kong. The test piles are embedded in superficial deposits and weathered rocks with various degrees of decomposition. In this paper, the pile load test results are interpreted and reported. A simple and rational method of back-analysis for long piles, using inclinometer data and assuming a fourth-order polynomial to represent the shape of soil reaction profile, is introduced. The method, requiring only simple spreadsheet-type operations, makes it possible to incorporate non-linear concrete behaviour in the back-analysis, and to deduce the p-y curves for future design of piles in similar ground conditions. In order to verify the rational method, an analysis is carried out using the back-analysed p-y curves, and the predictions are found to agree well with the measured pile head deflections. This proposed method demonstrates how p-y curves are back-analysed rationally for long piles embedded in complex ground conditions, in contrast to traditional back-analyses using recommended p-y curves for a uniform soil stratum. [ABSTRACT FROM AUTHOR]

In this column, John E. Dvorak provides insight into some of the best industrial hemp websites on the Internet. Areas covered in detail include news portals, hemp associations, new products and research sites. Reviews relating to specific topics such as hemp food, textiles, paper and other industrial uses will also be periodically touched upon. The ever-changing nature of the world wide web will be reflected in the many different types of websites reviewed. While the focus of this column is on North America, a concerted effort is being made to incorporate as many sites from as many countries as possible. [ABSTRACT FROM PUBLISHER]