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Ward R. Malisch spent most of his 50-year career addressing issues related to concrete construction, specifically to problems that concrete contractors deal with daily. His civil engineering training began at the University of Illinois at Urbana-Champaign where he received his BS, MS, and PhD in 1961, 1963, and 1966, respectively. During his time at Illinois he also carried out research on concrete durability and taught courses on plain concrete. Following that, he taught courses in concrete construction at the University of Missouri-Rolla (now Missouri University of Science and Technology) where he received several awards for outstanding teaching. During his time there he took a leave of absence to work in quality control for the prime contractor building Missouri’s first nuclear power plant. This experience spurred his interest in how specification requirements and tolerances affected contractors’ abilities to build both simple and complex structures. Malisch was able to reach the construction industry more directly when he joined the staff of the World of Concrete seminar program and later became editor of Concrete Construction magazine. He was then able to teach at a national level by further developing a seminar program and editorial content that featured how-to-do-it information on concrete technology, with an emphasis on contractor-related topics. During his tenure with the magazine, he began answering questions on a telephone hotline service offered by the American Society of Concrete Contractors (ASCC), and gave advice on problems related to unrealistic concrete tolerances, inadequate knowledge about plastic concrete properties, ambiguous specifications, and a wide range of other construction-related topics. In subsequent years, Malisch served as director of engineering and later as senior managing director at the American Concrete Institute. There, while supervising the engineering, marketing, and education departments, and serving as publisher of Concrete International magazine, he also interacted with other concrete-related organizations, serving on the Research, Engineering, and Standards Committee of the National Ready Mixed Concrete Association and on the ASCC Board of Directors. Along with the ACI Strategic Development Council, ASCC, and Construction Technology Laboratories, he helped to organize an Inter-Industry Working Group on Concrete Floor Issues that brought together leaders from several construction and flooring industry groups. One outcome of this group’s activity was publication of ACI 302.2R-06, “Guide for Concrete Slabs that Receive Moisture-Sensitive Flooring Materials.” Upon retirement from ACI in 2008, he was named technical director of ASCC. He was active again in forming an Inter-Industry Working Group on Reducing the Cost of Tolerance Compatibility Problems along with eight other co-sponsoring groups. He later served as principal investigator on two construction related research projects dealing with contractor-related problems. Dr. Malisch’s awards include: • 1986— Elected Fellow of the American Concrete Institute • 2004— Arthur Y. Moy Award, ACI Greater Michigan Chapter • 2006— Silver Hard Hat Award, highest award given by the Construction Writers Association • 2008— Richard D. Gaynor Award, Highest technical award given by the National Ready-Mixed Concrete Association • 2009—One of Concrete Construction magazine’s Most Influential People • 2010— Arthur R. Anderson Medal, ACI, given for outstanding contributions to the advancement of knowledge of concrete as a construction material • 2011— ACI Construction Award, given to the author of any paper of outstanding merit on concrete construction practice • 2011— ASCC Lifetime Achievement Award, ASCC’s highest honor, acknowledging recipients for their body of work within the industry and their service to ASCC • 2013— ACI Honorary member, given to a person of eminence in the field of the Institute’s interest or one who has performed extraordinary meritorious service to the Institute • 2019—Roger H. Corbetta Concrete Construction Award, ACI, given to an individual that has made significant contributions to progress in methods of concrete construction. For his dedication to the concrete construction industry, this Special Publication is a tribute to his work and is sponsored by the ACI Construction Liaison Committee. Sixteen presentations, distributed in four sessions named “Ward R. Malisch Concrete Construction Symposium,” were given at the 2017 ACI Fall Convention in Anaheim, CA. The quality of the presentations was highlighted by the participation of four former presidents of ACI: David Darwin, Terry Holland, Ken Hover and Mike Schneider. The nine manuscripts presented in this Special Publication are significant in that each paper represents authors that have been previously published in ACI. Thanks are extended to the many ACI members who reviewed the manuscripts and provided helpful technical and editorial comments which enhanced the authors’ papers. This Special Publication is but one small token of appreciation and gratitude to the more than 50-year service of Ward R. Malisch to concrete construction. He has been a source of inspiration to many as well as an example of honesty, integrity, and dedication. He has built the foundation for others to build upon in serving the concrete construction industry.

Bugholes on as-cast surfaces are an aesthetic issue, not a performance issue related to strength, durability, or serviceability. Because they are an aesthetic issue, attempts to evaluate bugholes objectively, with measurements, are not useful. Measuring bugholes using an evenly divided scale or other instrument can reveal their number, individual area, and total area as a percentage of a sample area. But there is no scale or instrument for aesthetic judgments. Thus, matching a mock-up surface with the as-cast surface, although subjective, is a better method for acceptance of surface appearance.

Two characteristics are of primary interest to those using floor surfaces – the surface bumpiness (flatness) and the levelness. Prior to publication of the 2006 cycle of the ACI 117 document, the ACI 117 committee completed an exhaustive study of the floor surface characteristics evaluated by the F-Number System, The 10-Foot (3 m) Straightedge approach, and the Waviness Index System. The purpose of the study was to evaluate each of the methods and to develop tables that establish a small degree of uniformity among the various tolerance approaches. The F-Number System and Waviness Index use data taken at regular intervals along lines located in random locations on the test surface. The 10-Foot (3 m) Straightedge approach uses a straightedge placed in any location on the floor surface. The largest gap between support points is then measured. Each of the methods utilizes different criteria to evaluate data, so it is important for the specifier to understand the specific surface characteristics controlled by each of the methods. The ACI 117 committee evaluated a set of 600 floor surface profiles. Each of the profiles was 100 feet in length. Six groups of F-number pairings were developed as follows: FF 20/FL 15; FF 25/FL 20; FF 35/FL 25; FF 45/FL 35; FF 60/FL 40; FF 100/FL 60; each of the groups contained 100 profiles. Both the Flatness F-number and Levelness F-number for each of the profiles in each group were within 5% of the respective target values. For each of the 600 profiles, the gap-below-the-straightedge and waviness index statistics were calculated. Results from the study are presented.

PCA researchers interested in the problem of evaporation of bleed water from concrete surfaces borrowed an equation developed by hydrologists to predict evaporation from Lake Hefner in Oklahoma. PCA’s graphical representation of that equation, subsequently modified to its present form by NRMCA, was later incorporated into multiple ACI documents, and is known by concrete technologists world-wide as the “Evaporation Rate Nomograph.” The most appropriate use of this formulation in concrete construction is to estimate the evaporative potential of atmospheric conditions (known as “evaporativity”). Since the difference between actual and estimated evaporation rate can be in the range of ± 40% of the estimate, best use of the equation as routinely applied is as a semi-quantitative guide to estimate risk of early drying and inform decisions about timing and conduct of concrete placing and finishing operations. Use of the “Nomograph” and related “Apps” in specifications is more problematic, however, given: 1.) the inherent uncertainty in its underlying equation, 2.) the difficulty in obtaining input data that appropriately characterize jobsite microclimate, and 3.) establishing a mixture-specific criterion for tolerable evaporation rate.

During hot weather concreting, contractors have several options for dealing with slump loss and rapid drying of concrete surfaces. Limiting slump loss requires cooperation between the concrete producer and contractor, especially with respect to reducing truck waiting time. Several options for minimizing surface drying are compared, based on effectiveness and cost. Finally, providing for adequate initial curing of concrete test cylinders can reduce the possibility of schedule delays and increased costs related to low strength-test results.