Design Manual on the European Recommendations for the Fire Safety of Steel Structures

European Recommendations for the Design of Longitunally Stiffened Webs and of Stiffened Compression Flanges

Guide to Earthwork Construction

TRB State of the Art Report 8: Guide to Earthwork Construction provides construction engineers and technicians with information on all aspects of earthwork construction. Although it is not intended to be a design manual, it does contain considerable background on the design concepts that are necessary for good earthwork construction.

Advances in Meshfree and X-Fem Methods

AGGREGATES IN SELFCONSOLIDATING CONCRETE

Self-consolidating concrete (SCC) is an advanced type of concrete that can flow through intricate geometrical configurations under its own mass without vibration or segregation. A research project was conducted to investigate the role of aggregates in SCC. Although SCC can be proportioned with a wide range of aggregates, the selection of favorable aggregate characteristics can significantly enhance the economy and performance of SCC. The objectives of the research project were to evaluate the effects of specific aggregate characteristics and mixture proportions on the workability and hardened properties of SCC, to identify favorable aggregate characteristics for SCC, and to develop guidelines for proportioning SCC with any set of aggregates. The effects of aggregate grading; maximum size; shape, angularity, and texture; clay content; and packing density were evaluated. Separately, the effects of mixture proportions, cementitious materials, and chemical admixtures were evaluated. In total, 12 fine aggregates, 7 coarse aggregates, and 6 microfines were tested. Tests were conducted on paste, mortar, and concrete. Paste measurements were conducted to evaluate the effects of cement, fly ash, microfines, high-range water-reducing admixture (HRWRA), and viscosity modifying admixture (VMA) on rheological properties. Mortar measurements were conducted to evaluate the effects of fine aggregates, microfines, and mixture proportions on workability and hardened properties. Concrete measurements were conducted to evaluate the effects of fine aggregates, coarse aggregates, microfines, and mixture proportions on workability and hardened properties. Target properties for SCC workability were defined as a function of the application and in terms of filling ability, passing ability, segregation resistance, and rheology. Seven workability test methods were evaluated extensively to provide sound, engineering justifications for their use and for the interpretation of their results. Specific tests for filling ability, passing ability, and segregation resistance were recommended. Based on the results of this research and well-established principles from the literature, a mixture proportioning procedure for SCC was developed. The procedure is based on a consistent, rheology-based framework and was designed and written to be accessible and comprehensible for routine use throughout the industry. In the procedure, SCC is represented as a suspension of aggregates in paste. In order to achieve SCC workability, the paste volume must be sufficient for the given aggregate blend and the paste rheology must be selected based on the aggregate blend and paste volume. The three-step procedure consists of selecting the aggregates, paste volume, and paste composition. Detailed recommendations are provided for each step. Aggregates are selected on the basis of grading, maximum size, and shape and angularity. The paste volume is set based on the aggregate characteristics. The paste composition is established to achieve workability and hardened properties. All required testing is conducted with methods standardized by ASTM International.

PRACTICAL DESIGN AND INSPECTION GUIDE FOR HELICAL PILES AND HELICAL TENSION ANCHORS

This design guide was originally prepared for a short course presented by the author and Kevin M. McNeill, P.E., of D&B Engineering Contractors, Inc., on August 3, 2000, in conjunction with the GeoDenver 2000 Geotechnical Engineering Conference sponsored by the American Society of Civil Engineers. This Fourth Edition is an update of the Third Edition published in June, 2004.
The material presented herein is the result of the author’s experience and knowledge in designing, specifying, installing, inspecting, and monitoring performance of helical piles and tension anchors since 1986. Much of the author’s experience is with helical piles and tension anchors manufactured by Hubbell/Chance. Since 2005, experience has also been with helical piles and helical tension anchors manufactured by International Marketing & Research, Inc. (I.M.R.), Denver, Colorado, U.S.A., under the brand name “HELI-PILE®.” This book is intended to be a practical design and inspection guide/reference for engineers and other foundation professionals. This design guide is the sole work of the author. No guarantee or warranty is expressed or implied by the author or I.M.R. As always, the information presented herein must be coupled with sound engineering judgment.
The author acknowledges the contribution of Mr. Robert L. Jones, Chairman of I.M.R. and D&B Engineering Contractors, Denver. Without Mr. Jones’ assistance, this book would not have been possible. Mr. Jones is one of a select group of serious pioneers of helical pile technology in the world. His foresight has led his companies to the forefront in the field. Mr. Jones was the first in the world to use helical piles for the repair of failed lightly loaded residential foundations constructed on highly expansive clay soils. He is among the first in the world to seriously use helical piles for construction of new foundations of lightly loaded residential structures on highly expansive soils. Subdivisions of homes are now being constructed on helical piles. Multiple-story commercial structures with heavy loads are now constructed on helical screw piles, thanks largely to Mr. Jones’ persistence in showing the engineering and construction community that they work, even over the long haul. It is estimated that in the last 23 years D&B Engineering Contractors has installed nearly 200,000 helical screw piles in the Front Range area of Colorado. As of this writing, no properly designed and installed helical piles installed by D&B have failed. This is a credit to Mr. Jones’ demand for high quality control and his insistence on using correct procedures and materials by knowledgeable engineers and trained installation personnel. Mr. Jones has also been involved in countless helical pile and tension anchor projects throughout the Western United States with his manufacturing and distribution company, I.M.R., Inc.
The author acknowledges the contributions of Dale Jones of D&B Engineering Contractors, Sammy Irvin of Foundation Specialists & Repair, and Jared Dalton, Richard Dalton, and Jim Dalton of Intermountain Helical Piers Corporation, all dedicated specialty helical pile installation contractors whose photographs and drawings of structures founded on helical piles and specialized helical pile installation equipment appear herein.