Brittle Matrix Composites 9
Brittle Matrix Composites 9

Author: A M Brandt

Publisher: Elsevier

Published: 2009-11-30

Total Pages: 464

ISBN-13: 085709307X

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The subjects of the symposia are on composite materials with matrices behaving as brittle in normal or special conditions. Brittle matrix composites are applied in various domains (civil engineering, mechanical equipment and machinery, vehicles, etc.) and in the last decades their importance is increasing together with their variety. Papers include: aggregate-binder composites (concretes, fibre concretes, rocks); sintered materials (ceramics); high strength composites with brittle matrices. In principle, the general problems of structures made of composite materials are not included in the papers. Various approaches to the material engineering problems are presented in the papers.

Brittle Matrix Composites
Brittle Matrix Composites

Author: Tatiana V. Lyashenko

Publisher: Elsevier Inc. Chapters

Published: 2012-11-12

Total Pages: 17

ISBN-13: 012809026X

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Fibre reinforced polymer-cement compositions for self-levelling flooring are studied. The individual and combined effects of dispersible polymer powder with properties of binder and superplasticiser, of various methylcelluloses, and of polypropylene fibre on effective viscosity of the mix and mechanical properties of the hardened mortar are evaluated and analysed. Used for analysis are multifactor experimental-statistical models built on the data obtained for 18 mixes (of the same workability) in the designed experiment and describing the fields of rheological model parameters, of strength, and other criteria in composition coordinates. The models have made it possible to simulate material behaviour in computational experiments, to reveal and evaluate the correlations of the properties for different technological conditions, to find individual and compromise optima.

Brittle Matrix Composites
Brittle Matrix Composites

Author: Agnieszka J Klemm

Publisher: Elsevier Inc. Chapters

Published: 2012-11-12

Total Pages: 18

ISBN-13: 012809012X

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Construction industry like any other area of economic and social life undergoes continuous alterations and improvements in order to successfully comply with the requirements of sustainable development. Consumers demand more durable, less labour and service intensive materials at a competitive price. To meet these expectations numerous new composite materials have been developed over the last couple of decades, including cementitious materials modified by superabsorbent polymers (SAP). The paper presents part of the larger research project on the performance of cementitious mortars containing two types of superabsorbent polymers (SAP) as the internal curing agent.SAP A is a copolymer of acrylamide and acrylic acid and SAP B is a polymer based on acrylic acid. Research work presented in this paper involves macro and micro scale characterisation of polymer modified mortars. The microstructural features were studied with application of the Mercury Intrusion Porosimetry and the Scanning Electron Microscopy techniques. Analyses of pore size distribution in mortars of different ages are accompanied by the analyses of strength and autogenous shrinkage development as well as early density changes in immature mortars by the X-ray absorption method. The investigations confirmed the positive effect of SAP A on the reduction of autogenous shrinkage and microcrack propagation. Limited absorption/desorption abilities of SAP B cannot reassure continuous supply of water and hence the performance of SAP B mortars was comparable with the reference samples. The effect of both SAPs on strength development proved to be negligible.

Brittle Matrix Composites
Brittle Matrix Composites

Author: Dominik Logoń

Publisher: Elsevier Inc. Chapters

Published: 2012-11-12

Total Pages: 17

ISBN-13: 0128090308

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The paper presents the methods of controlling sedimentation of cement mix using D-cube flow, slump, cone immersion and electrical resistance tests. These methods make it possible to control the sedimentation of aggregates and fibers, the optimization of different admixtures and additives and the rheological properties of cement mixes. The electrical resistance test for cement composites was modified. The cube (150x 150x 150mm) was equipped with two electrodes to measure the resistance of the mix. For sedimentation measurement electrodes were placed in the upper and bottom part of the mix. Measured changes of the resistance at different depths of the mix give the information about the sedimentation of components. The main advantage of the D-cube (150x150x150 mm) flow, slump and cone immersion tests is the ability to do it without advanced measuring devices and the fact that one method is sufficient to compare the rheological properties of cement pastes, mortars and concretes.

Brittle Matrix Composites
Brittle Matrix Composites

Author: Piet Stroeven

Publisher: Elsevier Inc. Chapters

Published: 2012-11-12

Total Pages: 18

ISBN-13: 0128090286

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This paper will discuss novel techniques for pore network exploration and the assessment of topological and geometrical characteristics relevant for durability estimation. The discussed methods are applicable to DEM-produced cementitious materials in which binder particle are realistically dispersed. This cannot be achieved by the in concrete technology popular random generator-based systems. Development of the discussed techniques was inspired by the path finding algorithms developed in robotics. The presented techniques are called double random multiple tree structuring (DraMuTS) and random node structuring (RaNoS). The path finding algorithms are adapted to the porosimetry problem and as a consequence modified to exclude time-consuming iterations. Moreover, path finding will take place starting from a large number of positions to enhance the economy of the approach.

Brittle Matrix Composites
Brittle Matrix Composites

Author: Tomasz Ponikiewski

Publisher: Elsevier Inc. Chapters

Published: 2012-11-12

Total Pages: 18

ISBN-13: 0128090278

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The paper presents results of tests on self-compacting mixtures with the addition of steel fibres (Steel Fibre Reinforced Self-Compacting Concrete). Four types of steel fibres at 3 levels of the volume ratio are considered. The results include studies on samples belonging to classes of slump flow SF, classes of viscosity T500, and rheological tests. The studies were based on application of two rheometers for rheological properties of concrete mixtures - BT2 Rheometer and Viskomat XL. Additionally, a study of compressive strength fcm,28 and flexural strength f was carried out on concrete SFRSCC. These studies have confirmed the possibility of using steel fibres in concrete SCC while maintaining the assumed technological parameters for concrete mixtures and, above all, their workability.

Brittle Matrix Composites 10
Brittle Matrix Composites 10

Author: A M Brandt

Publisher: Elsevier

Published: 2012-11-12

Total Pages: 422

ISBN-13: 0857099892

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The subjects of the symposia are on composite materials behaving as brittle, normal and special conditions of exploitation. Brittle matrix composites are applied in various domains and the series of symposia are closely related to their applications in civil engineering. In the last decades their importance is increasing along with their variety and the use of most advanced methods of testing. Papers include concretes, fibre concretes and ceramics, particularly their composition, microstructure and fracture processes. Various new and advanced engineering problems are presented in the papers.

Composite Materials
Composite Materials

Author: Charles E. Bakis

Publisher: ASTM International

Published: 2003

Total Pages: 394

ISBN-13: 0803134657

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"The 14th ASTM Symposium on Composite Materials: Testing and Design, was held March 11-12, 2002 in Pittsburgh, PA. The Testing and Design symposia, sponsored by Committee D30 on Composite Materials, have been scheduled on a roughly bi-yearly basis since 1969 to provide a forum for researchers and practitioners to meet and exchange their latest methods and findings related to the testing and design of composite materials and structures."