International Concrete Abstracts Portal

Buildings in Chile are mostly structured with reinforced concrete walls. This structural system has been used for the construction of residential buildings since 1930. The use of structural walls in such buildings provides adequate strength and stiffness. These characteristics have led to adequate seismic performance of structural wall buildings following the 1985 and 2010 earthquake in Chile. The seismic design of such buildings is conducted using the NCh433 and NCh430 codes. The NCh433 specifies the design spectra, the strength reduction factor and the intersory drift limits, where the use of structural wall buildings is promoted. The NCh430 is the concrete design code, which adopts ACI 318 with some modifications. This presentation will summarize the relevant aspects of the seismic design provisions for reinforced concrete wall buildings in Chile.

The primary focus of this guide is pavement construction. Modern slipform paving techniques and time-proven formed construction procedures are highlighted. Quality control, quality assurance, and construction inspection, as well as the environmental, economic, and societal benefits of concrete pavement, are also presented. This guide briefly reviews all aspects of concrete pavement construction for highways and, to some extent, local roads, streets, and airfields. Intended for field and office personnel, this guide provides a background on design issues that relate to construction and reviews material selection. Note that the materials, processes, quality control measures, and inspections described in this guide should be tested, monitored, or performed as applicable only by individuals holding the appropriate ACI certifications or equivalent. Keywords: concrete pavement; concrete pavement construction; concrete paving; fixed-form paving; paving materials; slipform paving; sustainability.

This presentation will summarize the major contributions of Dr. Hooton, specifically on the Canadian concrete industry.

An experimental investigation was conducted to examine the behavior of reinforced concrete (RC) beams subjected to service loads coupled with corrosion of the main flexural reinforcement. A total of nine beams with dimensions of 145 x 250 x 1800 mm (5.71 x 9.84 x 70.87 in.) were constructed. The main test variables were corrosion current density and level of service loading. The beams were loaded under a four-point bending test to either 60, 40, or 0% of the beam's ultimate capacity. Applied loads and reinforcement corrosion were sustained until the beams failed. Test results indicate that the failure of corroded RC beams becomes brittle, resulting in premature rupture of corroded steel bars. This behavior is attributed to the development of localized corrosion at sections with flexural cracks in beams. Furthermore, it was found that beams subjected to higher levels of service loading experienced further reductions in ultimate load capacity and ductility.

The influence of axial compression is not incorporated into the design provisions for concrete breakout or pryout strength of anchors under shear. This study experimentally evaluated the shear capacities of anchors subjected to axial compression on a base plate using ten large-scale specimens. The test variables included axial compression N, edge distances from the anchor shaft in the direction of applied shear, edge distances perpendicular to the applied shear, and the compressive strength of concrete. The results showed little difference in crack initiation and propagation with varying axial compression. However, axial compression significantly improved the concrete breakout strength of anchors in shear. The applied axial compression reached up to 2.5 times the mean concrete breakout strength V_cbgo, as determined by the Concrete Capacity Design (CCD) method, and the average increase in shear strength was approximately 0.6 times the applied compression. In addition, axial compression suppressed concrete pryout failure by preventing the uplift of base plates. Based on the lowest N/V_cbgo ratio used in the tests, if axial compression of at least 0.5V_cbgo is applied to a base plate, pryout failure need not be considered.