ACI 224 . 3 R-95 Joints in Concrete Construction Reported by ACI Committee 224
nance of joints in concrete structures subjected to a wide variety of use and environmental conditions. In some cases, the option of eliminating joints is considered. Aspects of various joint sealant materials and jointing techniques are discussed. The reader is referred to ACI 504R for a more comprehensive treatment of sealant materials, and to ACI 224R for a broad discussion of the causes and control of cracking in concrete construction. Chapters in the report focus on various types of structures and structural elements with unique characteristics: buildings, bridges, slabs-on-grade, tunnel linings, canal linings, precast concrete pipe, liquid-retaining structures, walls, and mass concrete.
RIGID PAVEMENT ANALYSIS AND DESIGN
This study was conducted to characterize and compare currently available rigid pavement analysis models and design methods and to develop new rigid pavement designs to be evaluated in full scale experimental projects in an actual highway environment. The analysis models considered include: ILLI-SLAB, JSLAB, WESLIQID, WESLAYER, JCS-1, H51, CRCP-2, and RISC. The design methods include: 1985 AASHTO Guide, Zero Maintenance JCP-1, California DOT, PCA, RPS-3 Texas SDHPT, ARBP-CRSI and Illinois DOT. The capabilities, limitations, and assumptions of each of these models and methods are discussed in detail to assess their adequacy to assist in the design and analysis of rigid pavements. Based upon the results obtained, several models and methods are recommended for use in the development of new rigid pavement designs. A set of rigid pavement designs, featuring trapezoidal cross sections, widened truck lanes, permeable drainage layer, longitudinal drainage pipe, precoated dowels, shorter joint spacing (for JRCP) and tied PCC shoulders was developed for field testing through experimental projects in the various climatic zones of the United States. A project description form (PDF) is provided for the interested State agencies. Guidelines were developed for joint load transfer design and joint spacing. Predictive models for doweled and nondoweled joints were developed (A).
Thorium-induced Anatomical and Histopathological Changes in Liver of Swiss Mice
ObjectivePresent study is aimed to investigate the anatomical and histopathological changes in liver tissues of Swiss albino male mice, one month after intravenous administration of thorium (232Th; 4 and 40 mg/kg).MethodsSynchrotron X-ray micro-CT imaging, CD31 immuno-cytochemistry, hematoxylin & eosin staining and Periodic acid-Schiff staining were performed to study changes in liver anatomy, blood vessels/capillaries, histology and glycogen content of liver, respectively.ResultsSynchrotron X-ray micro-CT imaging of liver showed loss of blood vessels in mice treated with thorium (4 mg/kg), which was more prominent at higher dose of thorium (40 mg/kg). These thorium-induced changes in liver were correlated with the decrease in CD31 positive cells and loss of tissue architecture. A dose-dependent increase in glycogen content was also observed in the liver of thorium-treated mice.ConclusionOur results provide novel insight about the effects of thorium on liver, which may have significant implications in understanding the mechanism of thorium thorium-induced hepatotoxicity.