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1、A C 1 SP-ILL A7 m ab 85 5 m - = - _ _ _ _ - - / - Polymers in Concrete: Advances and Applications . 1 . - Peter Mendis Charles McClaskey Editors COPYRIGHT ACI International (American Concrete Institute) Licensed by Information Handling Services COPYRIGHT ACI International (American Concrete Institut
2、e) Licensed by Information Handling Services A C 1 SP-LLb 89 = ObbZ799 0007686 7 = I- Polymers in Advances and Concrete: Applications American Concrete Institute, Detroit Peter Mendis Charles McClaskey SP-116 Editors - COPYRIGHT ACI International (American Concrete Institute) Licensed by Information
3、 Handling Services COPYRIGHT ACI International (American Concrete Institute) Licensed by Information Handling Services I A C 1 SP-LLb 87 = 0662749 0007b87 7 I DISCUSSION of individual papers in this symposium may be submitted in accordance with general requirements of the AC1 Fublication Policy to A
4、C1 headquarters at the address given below. Closing date for submission of discussion is February 1, 1990. All discussion approved by the Technical Activities Committee along with closing remarks by the authors will be published in the July-August issue of either AC1 Structural Journal or AC1 Materi
5、als Journal depending on the subject emphasis of the individual paper. The Institute is not responsible for the statements or opinions expressed in its publications. Institute publications are not able to, nor intended to, supplant individual training, responsibility, or judgment of the user, or the
6、 supplier, of the information presented. The papers in this volume have been reviewed under Institute publication procedures by individuals expert in the subject areas of the papers. Copyright1989 AMERICAN CON(SRETE INSTITUTE P.O. Box 19150 Redford Station Detroit, Michigan 48219 All rights reserved
7、 including rights of reproduction and use in any form or by any means, including the making of copies by any photo process, or by any electronic or mechanical device, printed or written or oral, or recording for sound or visual reproduction or for use in any knowledge or retrieval system or device,
8、unless permission in writing is obtained from the copyright proprietors. Printed in the United States of America Editorial production: Patricia Kost LIBRARY OF CONGRESS CATALOG CARD NUMBER 89-80360 COPYRIGHT ACI International (American Concrete Institute) Licensed by Information Handling Services CO
9、PYRIGHT ACI International (American Concrete Institute) Licensed by Information Handling Services PREFACE AC1 Committee 548 has sponsored six symposia since 1972 to help fulfill its mission to gather and evaluate information on the effects of polymers in concrete. The proceedings of the first five s
10、ymposia have all been published by AC1 and have received world-wide acclaim. This volume contains papers which were presented at two sessions during the 1988 AC1 Annual Convention in Orlando, Florida. The papers combine the development of new concrete polymer materials and the application technology
11、 of concrete polymer materials. M r , Peter Mendis andMr. Charles McClaskey served as Co-chairmen of the symposium, and I would like to express the gratitude of Committee 548 for their efforts in organizing and conducting the sessions as well as compiling the proceedings. The committee wishes to ext
12、end its sincerest appreciation to the authors whomade the proceedings possible, as well as those members who assisted the chairman by reviewing the printed papers. Jack J. Fontana Chairman, AC1 Committee 548 , 111 COPYRIGHT ACI International (American Concrete Institute) Licensed by Information Hand
13、ling Services COPYRIGHT ACI International (American Concrete Institute) Licensed by Information Handling Services A C 1 SP-116 7 W 06b2747 000767 2 W i AC1 C latex (plastic); par kins swctures; reinforced concrete; renovating; repairs; resurfachq; stwene- butadiene resins 1 COPYRIGHT ACI Internation
14、al (American Concrete Institute) Licensed by Information Handling Services COPYRIGHT ACI International (American Concrete Institute) Licensed by Information Handling Services 2 Imin Brian h i n is a Market Development Specialist with BASF Corporation in Chat- tanooga, Tennessee. He is a member of th
15、e American Concrete Institute, subcommittee 548A. He has twenty years experience in all phases of the concretejndustry. INTRODUCTION Deterioration of parking structures has become a costly concern. The typical method of concrete construction does little to resist the primary cause of deterioration.
16、Conse- quently, maintenance and repair costs are substantial. Understanding the reason for this detenoration is the first step in making a decision concerning selection of the repair process. Parking structure deterioration can be related to some or all of the following causes: (A) Poor concrete qua
17、lity assurance during the construction phase. (B) Lack of proper concretcover for the reinforcing steel. (C) Expansion joint leakage (D) Freeze-thaw cycle (E) Cracking (F) Deicing salts The main cause for deterioration is the use of deicing salts on roadways. Vehicles carry the salts onto the parkin
18、g structure. Melted ice transfers oxygen and dissolved salts through voids in the concrete to the surface of the reinforcing steel, initiating the corrosion process. The physical presence of corrosion products creates pressure, causing the concrete to crack. The sait laden water can then freely pene
19、trate the reinforcing steel and hasten the destructive corrosion process. Spalling and delamination ensue resulting in total detenoration of the parking structure deck. In recent years, several repair techniques have been used to attempt to repair parking structure decks. Some of these include the u
20、se of superplasticized concrete, silica fume concrete, low water-cement ratio, high air concrete, deck coatings and deck sealers, Each has inherent advantages and disadvantages that are not within the scope of this paper, but one should consider every technique when selecting a repair process. This
21、paper will address the use of BASF Styrofan 1186, Styrene-Butadiene latex modified concrete overlay as the method of rehabilitation for parking structure decks, specifically the Gateway Center Parking Garage in Pittsburgh, Pennsylvania. specifica- tions for the repair area and the production, placem
22、ent, finishing and curing of the latex modified concrete will be presented. BACKGROUND Latex modified concrete has been used primarily in the rehabilitation of bridge decks. Over 10,000 bridges have been rehabilitated using a Styrene-Butadiene latex modified concrete overlay. It has proved to be a l
23、ong lasting and cost effective repair method for this application. COPYRIGHT ACI International (American Concrete Institute) Licensed by Information Handling Services COPYRIGHT ACI International (American Concrete Institute) Licensed by Information Handling Services Polymers 3 Parking structure and
24、bridge decks are both subject to high concentration of deicing salts. It is expected that the excellent performance record established for latex modified concrete in bridge decks will be duplicated in parking structure repairs. COST FACTORS The final decision of a repair technique is usually based s
25、olely on economic considera- tions. In the rehabilitation of a parking structure, the tendency in the past has bcen to consider only the initial cost of the repair. In such instances, latex modified concrete overlays are precluded. StyreneButadene latex modified concrete overlays cost somewhat more
26、initially than other repair systems. However, when consideration is given to the extended life of the system and the low maintenance cost, overall costs are lower than those for alterna- tivesystems. (bridge deck repair data projects a twenty year life), A life cycle cost analysis has been prepared
27、by Wiss, Janney, Elstncr mecast concrete; safety; structural desicm corm uter procrrams ; drainaqe; economice; polymer 15 COPYRIGHT ACI International (American Concrete Institute) Licensed by Information Handling Services COPYRIGHT ACI International (American Concrete Institute) Licensed by Informat
28、ion Handling Services 16 Zanke About the Author Dr. Ulrich Zanke is a Professor of Civil Engin- eering at the University of Hannover, W. Germany. His research and development includes, experimental hydraulics, sediment transport, and coastal engin- eering and over 16 years of experience with Civil e
29、ngineering projects. . INTRODUCTION Drainage troughs are installed for the drainage of liquids from firm surfaces. Typical axeas include, parking areas, athletic fields or airport surfaces, from which precipitated water must be drained. Another important area is floor surfaces in facilities such as,
30、 the chemical and food processing industry, in which, in addition to water, industrial liquids must also be removed reliably. As a rule the inflow comes from the side, but depend- ing on locality, an additional amount of water must also be accommodated from above. The surfaces to be drained do not a
31、lways have the same width so that the time inflow into the channels can vary over their length. If one must figure on an increased inflow of solids, purification systems, which partially block the flow cross section, must be estimated. Futhermore back-up (damming) effects can take place from connect
32、ing sewage systems. In such cases drainage channels must be designed safely as well as economically. For this purpose empirically sized precast polymer concrete channels of different nominal widths and cross-sectional shapes as well as various floor constructions (without drop, step-wise slopes, con
33、tinuous slopes) have been utilized. Using this method, the upper parts of longer channels, which experience less loading, are designed to be smaller. Until now the designing of such drainage lines present- ed problems in practice because of the time required to carry out the complex calculations and
34、 the poten- tial for error inherent in these calculations. COPYRIGHT ACI International (American Concrete Institute) Licensed by Information Handling Services COPYRIGHT ACI International (American Concrete Institute) Licensed by Information Handling Services Polymers 17 SOLUTION METHODS Because of t
35、he described situations, a simple calcula- tion of the water levels and thus the carrying capa- city of the channels is not adequate using conventional flow formulas. To achieve the design goals of safety and economy, two methods can be considered; the hydraulic experiment and the calculation of the
36、 float (level) line differential equation. This paper presents the results of the hydraulics experiment and compares these with the calculated results obtained using special case sand accumulation“. To calculate the sand accumulation an additional iteration loop was inserted into the calculation. Th
37、e following method can be used for a small inflow of sand: The shear stress is calculated for every flow condition and is compared with the critical shear stress (SHIELD (1936). ZANKE (1982). If the actual shear stress is too small, a slight aggradation of the bottom occurs. In the opposite case, er
38、osion occurs until a firm bottom layer is attained. This control loop is iterated long enough until the hydro- mechanical and the sedimentological parameters are in tune. In this way one obtains step by step the sand bottom along the ducts. Attention must be paid here to the differences in roughness
39、 of the channels or the sand bottom, which have a distinct influence on the water levels. Corresponding labor- atory tests were conducted in the above-named in- vestigations at the TU of Graz so that comparison conditions with the calculation were available. Measurements and calculation are compared
40、 in figure 5. Taking into account the uncertainty, with which one can determine today the boundary “at rest/move- ment“ on the bottom, the result can be considered to be quite good. COPYRIGHT ACI International (American Concrete Institute) Licensed by Information Handling Services COPYRIGHT ACI Inte
41、rnational (American Concrete Institute) Licensed by Information Handling Services A C 1 SP-LLb 7 m Obb2747 0007708 2 m 18 Zanke HYDRAULIC TEST For the comparatively simple case of a prismatic channel with side inflow remaining constant labor- atory investigations were conducted, e.g., at the Technic
42、al University of Graz, with a channel section 10 m long (NEMECZEK, l o . . ) . Although one can set up a sizing diagram from such tests, a diagram thus obtained can be used only for the tested channel type and the inflow variations used in the test. For other channel types, line lengths or inflows w
43、ith different distributions, the results cannot be used. The same is true for the case of potential built-ins, such as channel cleaning facilities or supports for cover grates. These built-ins interfere with the water outflow, depending on degree of im- mersion. For the case of a production-caused c
44、hange in wall roughness the tests must be repeated. This means that for arbitrary configurations of inflow and channel type appropriate new test series must always be made. COPYRIGHT ACI International (American Concrete Institute) Licensed by Information Handling Services COPYRIGHT ACI International
45、 (American Concrete Institute) Licensed by Information Handling Services Polymers 19 NUMERICAL MODEL In the subject case calculations are considerably more flexible. The hydromechanical principles are known. They can be derived from the impulse expres- sion or taken from the literature (e.g. CHOW (1
46、959), SCHROEDER (1966), HENDERSON (1966). Depending on the type of simplifications that must necessarily be made, one obtains outwardly slightly different solutions which, however, hardly differ from each other as far as the results go. Thus one obtains, e.g., according to CHOW/HENDERSON the differe
47、ntial equation : , 2Q 3 gA2 dx J -Jv- s dx 1 - FrL h = depth of water Q = throughflow at position x x = running length = flow cross section = required slope g = gravitational constant JS Jv = loss in slope Fr = FROUDE number COPYRIGHT ACI International (American Concrete Institute) Licensed by Infor
48、mation Handling Services COPYRIGHT ACI International (American Concrete Institute) Licensed by Information Handling Services A C 1 SP-116 7 Obb2747 0007710 O 20 Zanke The equation cannot be solved fundamentally. It must be converted into a suitable differential form and solved numerically. Local flo
49、w losses result from the named built-ins and cross section dis- continuities. However, these flow losses again depend on the (at first still unknown) solution of the differential equation. This is also true for the wall friction losses, which themselves again occur. as an implicit equation (can be solved only by a series of trial calculations). Thus several implicit equations are immixed within each other. Because of the calculation expenditures and the susceptibility to errors a manual calculation makes no sense. For the simplest case, the drainage channel with cons