The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform

S. Chow - One of the best experts on this subject based on the ideXlab platform.

  • Thermo-directional Movement of wood and wood composites
    Wood Science and Technology, 1994
    Co-Authors: S. Chow
    Abstract:

    Thermal Movement of wood and wood composites was studied and compared with that of random and oriented phenolic foams. Cell orientation was a dominate factor determining the Thermal response of these structures. In dried wood, Thermal Movement in the direction parallel to the cells (longitudinal) decreased in dimension during heating while the radial and tangential directions expanded under similar heating condition. Oriented foams showed more restraint in Thermal Movement in the parallel to orientation direction. These findings indicate constraining forces act on the direction parallel to the cells while more flexibility exists in perpendicular directions. Wood element size and orientation and the manufacturing process also influence the Thermal response in wood composites. The experimental results also revealed the potential fire hazard of waferboard type of composites.

J.j. Brooks - One of the best experts on this subject based on the ideXlab platform.

  • 13 – Thermal Movement
    Concrete and Masonry Movements, 2015
    Co-Authors: J.j. Brooks
    Abstract:

    The strain due to Thermal Movement caused by a change in temperature is equal to the product of the coefficient of Thermal expansion and the change in temperature. Consequently, Thermal Movement can be classified as reversible, except in the case of very young hardened cement paste where the Thermal coefficient of expansion changes with hydration during the period of temperature change. The Thermal expansion coefficient of concrete or masonry varies depending on the volume and type of aggregate or masonry unit and according to the composition of hydrated cement paste or mortar, its moisture content and age. In normal circumstances, the Thermal expansion coefficient is of interest over the seasonal temperature range (e.g., −20 to 80 °C in the UK).

  • Creep of Concrete
    Concrete and Masonry Movements, 2015
    Co-Authors: J.j. Brooks
    Abstract:

    Creep, elastic deformation, shrinkage, and Thermal Movement have to be taken into account in order to analyze concrete structures for long-term serviceability. Creep of concrete is a manifestation that the relation between stress and strain is a function of time and, since moisture Movement readily occurs in concrete under normal, ambient storage conditions, there are several categories of creep. Those categories are explained before proceeding to discuss in detail the many influencing factors affecting creep in compression: type and content of aggregate, water/cement ratio, stress/strength ratio, type of cement, age at loading, size and shape of member, storage environment, type of load, time under load, chemical and mineral admixtures, and temperature. After dealing with reversibility of creep or creep recovery and Poisson's ratio, tensile creep, cyclic creep, and creep resulting from other types of loading are discussed.

  • Effects of Movements, Restraint and Movement Joints
    Concrete and Masonry Movements, 2015
    Co-Authors: J.j. Brooks
    Abstract:

    In practice, it is rare that elastic strain, moisture Movement strain, creep, and Thermal Movement occur independently. Often they combine and may be restrained in a complicated manner to influence the Movement of the whole structure, or influence the deflection of individual elements especially when reinforced or prestressed steel is present. For example, restraint of drying shrinkage induces tensile stress, which is relieved to some extent by creep, but cracking will occur if the stress exceeds the tensile strength. Effects of Movement can be accommodated successfully by the incorporation of gaps or Movement joints and the inclusion of mortar bed joint reinforcement in masonry with openings. This chapter deals with problems caused by the effects of Movements and restraint, and Movement joints for both masonry and concrete buildings. Topics include types of joint, properties and types of fillers and sealants, estimation of total Movement, accuracy of construction, and design of joint width.

Zhao Guang-jie - One of the best experts on this subject based on the ideXlab platform.

  • Effects of periodic temperature changes on stress relaxation of chemically treated wood
    Forestry Studies in China, 2004
    Co-Authors: Xie Man-hua, Zhao Guang-jie
    Abstract:

    In order to clarify the relationship between the microstructural changes and the rheological behaviors of four chemically treated woods (delignified wood, hemicellulose-removed wood, DMSO swollen and decrystallization treated wood), the stress relaxation of wood with three different moisture contents was determined during periodic temperature changes. The experimental results show that after wood relaxation for 4 h at 25 °C, the stress decays sharply when the temperature increases and 2 h later the stress recovers again when the temperature drops back to the original point. The additional stress relaxation, produced after temperature begins to increase, is mainly caused by the Thermal swelling, molecular Thermal Movement and the break of a part of residual hydrogen bonds. The number of hydrogen bonds and the size and amount of cavities in various treated woods greatly affect the magnitude of the additional relaxed stress and the recovery stress.

J C Nicholls - One of the best experts on this subject based on the ideXlab platform.

  • Durability of continuously reinforced concrete surfaced with asphalt
    2008
    Co-Authors: K E Hassan, J C Nicholls, H M Harding, M E Nunn
    Abstract:

    This report presents designs for durable continuously reinforced concrete pavements (CRCP) with low-noise asphalt surfacing. It is based on research and measurements made on full-scale roads sites to determine the amount of reflection cracking in the concrete, and the seasonal Thermal Movement, These showed that thin surface course systems can be successful in bridging cracks in sound CRCP. Using an analytical approach, the reduction in CRCP slab thickness which can be achieved, for the same traffic loading, by the addition of asphalt surfacing, was determined. The results of this work were used to develop a family of design curves for CRCP with an asphalt overlay curve for a range of concrete flexural strengths and foundation classes.

  • Laboratory Tests on High-friction Surfaces for Highways
    1997
    Co-Authors: J C Nicholls
    Abstract:

    A series of test protocols are proposed which define a laboratory test programme to assess the performance of high-friction surface systems. The programme involves three simulative tests (for scuffing, wear and tensile adhesion), a Thermal Movement test and three conditioning tests (for heat-ageing, freeze/thaw and diesel susceptibility). Three optional tests (installation temperature, substrate texture depth and concrete substrate) are also proposed for use when specific claims for the system under test by the Supplier need to be substantiated and a general procedure for assessing the visual condition of trial sites is proposed. An additional test, the peel-off test, was considered but is not included in the proposed assessment programme. (A)

R. Rucinski - One of the best experts on this subject based on the ideXlab platform.

  • D0 Solenoid Upgrade Project: Thermal Contraction Analysis for the D0 Solenoid Chimney
    1993
    Co-Authors: R. Rucinski
    Abstract:

    This engineering note documents the Thermal contraction analysis that was done for the D-Zero solenoid chimney. The analysis was done as support of the 'Design Report of the 2 Tesla Superconducting Solenoid for the Fermilab DO Detector upgrade.' The cryogenic LHE and LN2 lines were analyzed for combined pressure, Thermal Movement, and dead weight. The tubing was stress analyzed per ASME code for Pressure Piping, standard ANSI AS:ME B31.3, for eight combinations ofThermal loading. A commercial pipe stress analysis and design system by Algor{reg_sign} was used for the analysis. Stresses calculated were well below allowables. Based on the analysis, the cryogenic lines will be installed at an offset from the vacuum jacket centerline so that during steady state cold operation, the cryogenic lines will be in a proper location.