Journal of Construction Engineering and Management

Masonry failure investigation often requires the documentation of the surface condition of walls. The types of information required for a masonry surface condition survey are Ksted. Among these is surface topography to define the locations and magnitude of lateral displacement and misplacement of the facade. A method is described for determining facade topography from a distance, i.e. from the ground and without touching the facade. The method has been tested and found useful.

Published bidding models have traditionally been approached from the point of view of the bidder or contractor. This paper deals with the analysis of more than 5,000 tenders comprising approximately 34,000 bids which were received by the specifiers. It was found that similar recognizable statistical frequency distributions existed in three different countries. It is therefore postulated that there exists a typical behavior pattern which can be represented by this frequency distribution. It was also postulated that the coefficient of variation of a tender is indicative of the risks which the bidders perceived. The means of the frequency distributions of the coefficients of variation also appear to be independent of the country, the type of construction industry, the economic climate, or time.

Jurisdictional disputes in the construction industry have long been a source of lost productivity. While dispute causes have been documented else‐where, the mechanisms for resolving disputes are explored here. Two alternatives are possible, namely: (1) The National Labor Relations Board; and (2) the Impartial Jurisdictional Disputes Board. For each approach, the organization, resolution process, appeal and injunctive relief opportunities, decision time frame, and decision criteria are documented. The two approaches are compared, and the advantages and disadvantages for each are cited. These assertions are based upon interviews and questionnaires. More than 60 industry and union officials participated. It is concluded that a voluntary procedure is highly desirable. The major barriers to developing a satisfactory procedure are: (1) Decision criteria; (2) enforcement authority; (3) contractor stipulation; and (4) scope of application. By far, the most difficult issue is that of decision criteria. The unions want the primary criterion to be past agreements of record and established trade practices. Contractors want more emphasis on efficiency and good management practices. It is concluded that unless this issue is resolved, no voluntary procedure will be satisfactory.

Theoretical aspects are presented to evaluate the adequacy of work sampling as a surrogate productivity measure. A 10‐week study is described in which work sampling data were gathered simultaneously with earned value information for a 10‐man, small‐bore pipefitter crew. Two forms of work sampling data were gathered that differed principally in the definition of direct work. The direct work percentages are statistically correlated to the ratio of earned to actual man‐hours, and it is shown that the Pearson product‐moment correlation coefficient could be improved by as much as 86% if the definition of direct work is restricted. The probability of a Type I statistical error is also greatly reduced. Data summarized according to 5‐ or 7‐day moving averages is found to be more reliable than daily or weekly averages. It is shown how a prediction equation could be developed. The slope of this equation suggests that rather significant changes in the earned to actual man‐hour ratio are reflected by rather small changes in direct work.

Probabilistic methods are being used increasingly in construction engineering. However, when a parameter is expressed in linguistic rather than mathematical terms, classical probability theory fails to incorporate the information. The linguistic variables can be translated into mathematical measures using fuzzy set and system theory. A construction management problem, i.e., estimation of the duration of an activity, is solved using this theory. In order to implement the proposed technique, various membership functions need to be estimated using judgment or with the assistance of experts. The proposed technique is not sensitive to small variations in the membership values. This is a very desirable property. However, the method is sensitive to the choice of the fuzzy relations. The uncertainty in the fuzzy relations can be modeled along with other sources of uncertainty. The mean and variance of the parameters involved in the problem under consideration are estimated here using a new method. The method maximizes the product of the sum of the membership associations for a certain frequency of occurrence and the corresponding frequency of occurrence. One of the main advantages of the proposed technique is that it can be easily implemented in existing computer programs for project scheduling.

Unionized contractors and construction unions are in difficulty today because of their apparent increasing lack of competitiveness with the non‐union sector of the industry. Probiems contributing to this are examined, as are efforts by labor, management, and others to remedy the problems. In Columbus, Ohio, labor and management established Operation MOST as a cooperative program to regain the share of the construction market lost to non‐union firms. This program encompasses a variety of activities and has been very successful. It is now being copied in various locations throughout the country. Several recommendations are made as to activities that should be undertaken by the parties to continue their cooperative spirit and to allow the unionized contractors to improve their cost competitiveness.

Published criticism in recent years concerning the inadequacy of Critical Path Method (CPM) as a project planning tool is identified and grouped under six major headings with reference to the publications in which the criticism were contained. These are answered from the writer's field experience and from experiences published by other authors. The object of the analysis is to see whether or not CPM as a project planning tool can meet the required functions of planning in construction, including consideration of legal and contractual framework and the complex and interdisciplinary nature of the project environment. The analysis reveals that, despite numerous criticism, project and construction planning should be done using CPM scheduling. Main factors affecting successful planning are realistic estimation of the productivity of crews in the context of expected job‐management efficiency conditions, and inclusion of sufficient time buffers between dissimilar trades. CPM is found to be equally useful as a planning tool for linear or repetitive projects. The limitations of this technique are identified in terms of the defined planning functions in the engineering phase of capital projects. A broad model for management of the engineering phase in revenue‐generating projects is suggested.

The findings of a study designed to investigate the costs and benefits of Minority Business Enterprise (MBE) regulations in the construction industry are presented. The data indicate that large contractors have less difficulty than smaller organizations in meeting MBE requirements. In addition, it is shown that the regulations both benefit and enlarge the number of minority contractors. According to the study, however, MBE procedures have not increased the number of qualified minority contractors. The data also indicate that MBE regulations have increased the cost of construction projects. The amount allocated, although significant when compared to percentage profit, is not substantial. For example, the unweighted values, in terms of construction dollar volume, range from 3.41% for the Engineering News‐Record (ENR) 400 organizations to 3.33% for the Associated General Contractors of Indiana, AGC (Indiana). The weighted values range from 2.04% for the ENR 400 contractors, to 3.74% for the AGC (Indiana). The great majority of firms surveyed indicate that MBE rules and regulations should be modified. Better agency procurement efforts and comprehensive programs to train minority contractors are mentioned as a necessity.

A minimum cost equipment replacement model based on the present worth of discounted‐cash‐flow is presented. The model uses arithmetic and geometric gradients to project the expected life cycle costs of the existing machine plus future replacements to an infinite horizon and then discounts them back to present value. Trial life spans of the existing unit, plus future replacement units, are then ranged until the combination which yields the minimum present value of total costs is determined. The general methodology is reviewed and its application illustrated with a sample problem.

Freshly placed (green) concrete is vulnerable to weakening of its properties if subjected to forces which disrupt the concrete matrix during the formative bond development process. Insufficient qualitative data, relating to the establishment of shock‐type vibration limits for green concrete has been found in the engineering community. This shortage of substantiative information and a job schedule requiring concurrent concrete placement and excavation blasting dictated the need to obtain reliable data on the extent to which green concrete could be shock‐vibrated without detrimental effects. An extensive laboratory and field test program provided conclusive information to support a significant increase in the commonly imposed green concrete shock‐vibration limits. Although green concrete was subjected to very high vibration levels, no critical damage limit was ever reached. Associated reinforcement bond tests questions the ACI 318–77 application of “Top Bar” factors to horizontal wall splices.

There is an imbalance in the visibility of costs of delays in the daily construction site work routine and the costs of overhead expenditures which to a large extent determine the magnitude of these delays. This imbalance frequently means that overhead expenditures are carefully scrutinized while delay costs may be totally ignored. The resulting suboptimization may not result in the lowest total project cost. A procedure is proposed to address this problem. The procedure works within existing cost accounting systems and is a modification of existing foreman-delay survey methods.