HIGHWAY RESEARCH BOARD DIVISION OF ENGINEERING AND INDUSTRIAL RESEARCH NATIONAL RESEARCH COUNCIL * * * Wa,•tinie Boad Problen,s * * * ' No.6 PATCIIING CONCRETE PAVEMENTS 1( • WITH CONCRE.TE HIGHWAY· RESEARCH BOARD 2101 Constitution Avenue, Washington 25, D, C. July, 1943 .. HIGHWAY RESEARCH BOARD * * * OFFICERS AND EXECUTIVE COMMITTEE Chairman, F. C. LANG, Engineer of Materials and Research, Minnesota Department of Highways, and Professor of Highway Engineering, University of Minnesota. Vice-Chairman, STANTON WALKER, Director of Engineering, National Sand and Gravel Association · THOMAS H. MAcDoNALD, Commissioner, Public Roads Administration WILLIAM H. KENERSON, Executive Secretary, Division of Engineering and Industrial Research, National Research Council T. R. AGG,. Dean, Division of Engineering, Iowa State College LION GARDINER, Vice-President, Jaeger Machine., Company PYKE JOHNSON, President, Automotive Safety Foundation W. W. MACK, Chief Engineer, State Highway Department of Delaware BURTON W. MARSH, Director, Safety and Traffic Engineering Department, American Automobile Association CHARLES M. UPHAM, Engineer-Director, American Road Builders' Association Director, RoY W. CRUM Assistant Director, FRED BURGGRAF DEPARTMENT OF MAINTENANCE W. H. RooT, Chairman COMMITTEE ON SALVAGING OLD PAVEMENTS C. L. MOTL, Chairman Maintenance Engineer, Minnesota Department of Highways Sub-committee on Salvaging Rigid Type Pavements A. A. ANDERSON, Chairman; Manager, Highways and Municipal Bureau, Portland Cement Association L. L. MARSH, Maintenance Engineer, Kansas State Highway Commission C. W. Ross, Maintenance Engineer, Illinois Division of Highways REX M. WHI'l"roN, Maintenance Engineer, Missouri State Highway Department IV a rti11ie R oa,l Pro b le11is There are two major wartime road responsibilities; to keep the traffic essential to the war effort moving, and to carry the existing roads through the war period in as good condition as possible. Dis­ charge of these responsibilities entails consideration of many new factors in view of the limitations on time, money, labor, equipment and use of critical materials imposed by the exigencies of the national situation. Obviously, changing emphasis from devising better and more economical methods to a program, within the wartime limita­ tions, of wartime traffic movement and conservation of the existing roads confronts highway engineers with many new problems and new aspects of old problems. The Highway Research Board believes that it can be helpful by aiding in disseminating in usable form the best available information on those phases of highway technology in which common practice has not become established 01; in which practice must be modified during the war. To this end a series of bulletins on WARTIME ROAD PROBLEMS will be prepared by qualified committees and published by the Highway Research Board. Recommendations in this series of bulletins are based upon wartime restrictions and needs and are only intended for use as guides during the periods in which these conditions prevail. This program has been endorsed by the Executive Committee of the American Association of State Highway Officials. Suggestions for suitable subjects will be welcomed. PATCHING CONCRETE PAVEMENTS WITH CONCRETE The best and most economical results in Figures 1 to 5 illustra te each type and patching with concrete have been ob­ give dimensions, IO(lll. ~ions and jointing tained where careful consideration has arrangements. been given to: The e types 1u·e brrsed on two-lane rural (1) Det.'l.il s of design of the patch. highway pavement. \:Vhere patching is . (2) Preparation of the area to be done on multi-lane pavement.'! or city patched. st reets, ·o me of tho design details may (3) Proportioning, placing, finishing and require modifi cation as described later. curing the concrete. Good practice requires tha t the longi­ As patching is usually d9ne without tudinal dimension of the patch be at least closing the road to traffic, methods of 4 ft. when the broken area lies at some dis­ handling t raffi c and providing nclequate tance from a transverse joint. Rectangu­ protection to the worker and to the b1· patches adjacent to and on one side f completed patch clming the cnring period a.11 expansion joint t' butt constrMtion are also involved. joint should not be less than 6 ft. long; The first step is to determine what areas those 1Ldjacent to nnd on one side of IL need repair and to mark the size and shape contraction joint should not, be les than of the places to be patched. M f~ rking 4 ft long. Reota11gular patches exteu.di.ng the areas involves consideration of the through n.n expansion joint or butt con­ condition of the existing pavement and struction joint should not be les than 6 the shape and dimensions of a patch that ft. long on either side of the join t; tho e will best stand up under traffic. at each extending through :i oo t1.trnction join t location. The selection and marking of should not be less than 4 ft. long on eithe1· the areas should be done by the mainte­ side of the joint. nance engineer in charge of the road. On full width patches (Fig. 1), whr br.eakage has occurred on each side of .. DESIGN tra nsverse joint, a minimum length of patch may be ust>.d by tihifting tl1 e position Size and Shape of the joint to one end of the p~tch tts The shape and dimenaio11s of a pn.tch indicated in F igure 1. On mult.i-h1110 pave­ 1,1, ncl its position in the pavement with ments wh ere no median strip is used, it is respect to edges and joint.~, are directly desirable to maintain the original positions related to its ability to stand up under of the transverse joints. In such cases a traffic. For this reason the patches have minimum 12-ft. length of patch (6 ft. on been grouped in five types according to either side of the joint) is used at expansion their location in the pavement as follows: joints and an 8-ft. length at contraction joints. Type When the breakage is in one lane only, 1. Full width patch- constructed a but extends from the edge the center lane-at-a-time. to width patch is necessa-ry. 2. Half width patch, involving a single j,oint,, a half Fo r details see Figure 2. In case rm expansion traffic lane. joint is included, it mu t be extended 3. Exterior edge patch. through the new concrete from its position 4. Interior edge patch. 5. Plug patch. Plug patches may be in the undisturbed lane. Better results rectangJ,Jl.ar or diamond shape. are obtained when the joint material is of The Ja.tter is used where bnd spall­ the same thickness and general character ing or interior corner breaks occur as that remaining in the original joint. and the concrete on the diagonals Rectangular patches less than one traffic is sound and strong. lane wide at an exterior or interior edge of 4 ( the pavement (Types 3 and 4, Figs. 3 and 4) most effective when the patch extends out have given best service when their width a distance of not less than 4 ft. nor more (transverse dimension) is not less than than 6 ft. from the centerline and is not 4 ft. nor more than 6 ft. so that the longi­ less than 4 ft. long. tudinal edge of the patch falls where there Diamond shape plug patches have been is a minimum number of wheel load appli­ used successfully for interior corner break­ cations. The length or longitudinal di­ age. Their shape and dimensions are mension should be not less than 4 ft. when shown in detail m Figure 5. They are [•p.insion Joint B A PATCH BETW[[N JOINTS PATCH AT EXPANSION JOINTS Ste. A·A CONSTRUCTION FIRST LANE SEC. A-A CONSTRUCTION COMPLETED 4'minimum Nol)•ellrudlng t.lller E,pans 10<1 joint .it end of patch SEC B·B SEC·C·C FIGURE 1-Type 1, Full Width Patch. Construction, lane-at-a-time the broken area is some distance from a built in one Jane at a time. Best results transverse joint; a minimum of 6 ft. on one have been obtained when the transverse or each side of a transverse expansion dimension on each side of the longitudinal joint; a minimum of 4 ft. on one or each joint is not less than 4 ft. and not greater side of a transverse contraction joint. than 6 ft. The overall longitudinal di­ Plug p1tches of either rectangular or mension is controlled by the angle formed dia~ond shape may be used for interior between the sides of the patch and the breaks which occur on both sides of the longitudinal center joint. For patches center joint. See Figure 5. some distance from joints this angle should Rectangular plug patches have been not be less than 30 nor more than 60 deg. 5 Le e At transverse expansion joints this angle Where the wheel loads do not exceed the should be not less than 30 nor more than load carrying capacity of the pavement as 45 deg. W11ere the diamond shaped plug a whole and where unsatisfactory sub­ patch CM be used, it effects a considerable grnde conditious hiw e been corrected, the saving in concrete ov r that required for a follo"ing thioknes es of patching are satis­ rectangular patch. factory (D in' Jt~gs. 1, 2, 3, 4:, 5) : E•pai'l9' 10n joint C . 6' min.imum II 6'mlnimum I Exist ng longitudinal joint SEC. A-A SEC. C-C ) SEC B-B Details of expansion joint in half ~ .ldth patch at original expanoion JOlnt. FIGURE 2-Type 2, H alf Width Patch Thickness of Patches 1.