Distribution Restriction Statement

Transcription

1 DEPARTMENT OF THE ARMY U.S. Army Crps f Engineers CEMP-ET Washingtn, DC ETL Technical Letter N December 96 Engineering and Design USE OF RESIN MODIFIED PAVEMENT (RMP) Distributin Restrictin Statement Apprved fr public release; distributin is unlimited.

2 Reprt Dcumentatin Page Reprt Date 31 Dec 1996 Reprt Type N/A Dates Cvered (frm... t) - Title and Subtitle Engineering and Design: Use f Resin Mdified Pavement (RMP) Cntract Number Grant Number Prgram Element Number Authr(s) Prject Number Task Number Wrk Unit Number Perfrming Organizatin Name(s) and Address(es) Department f the Army U.S. Army Crps f Engineers Washingtn, DC Spnsring/Mnitring Agency Name(s) and Address(es) Perfrming Organizatin Reprt Number Spnsr/Mnitr s Acrnym(s) Spnsr/Mnitr s Reprt Number(s) Distributin/Availability Statement Apprved fr public release, distributin unlimited Supplementary Ntes Abstract Subject Terms Reprt Classificatin unclassified Classificatin f Abstract unclassified Classificatin f this page unclassified Limitatin f Abstract UU Number f Pages 14

3 CEMP)ET DEPARTMENT OF THE ARMY ETL U.S. Army Crps f Engineers Washingtn, D.C )1000 Engineer Technical Letter December 1996 Engineering and Design USE OF RESIN MODIFIED PAVEMENT 1. Purpse. This letter prvides state-f-the-art guidance n the design and use f resin mdified pavement (RMP). 2. Applicability. This Engineer Technical Letter (ETL) is applicable t all HQUSACE elements and USACE Cmmands having military and civil wrks cnstructin respnsibility. 3. References. References prviding necessary general infrmatin, backgrund, definitins and design guidance fr resin mdified pavements are listed in Appendix A. 4. Discussin. a. Descriptin. Resin mdified pavement (RMP) is a cmpsite pavement surfacing that uses a unique cmbinatin f asphalt cncrete (AC) and prtland cement cncrete (PCC) materials in the same layer. The RMP material is generally described as an pen-graded asphalt cncrete mixture cntaining 25- t 35-percent vids which are filled with a resin mdified prtland cement grut. The pen-graded asphalt mixture and resin mdified cement grut are prduced and placed separately. The pen-graded mixture is prduced in a typical asphalt cncrete plant and placed with standard asphalt paving equipment. After the pen-graded layer has cled, the grut is pured nt the prus surfacing and vibrated int the internal vids. The RMP layer is typically 50 mm (2 in.) thick and has a surface appearance similar t a rugh-textured PCC. b. Materials and Cnstructin. The pen-graded asphalt mixture is designed t be the initial "skeletn" f the RMP. A carse aggregate gradatin with very few fines is used alng with a lw asphalt cement cntent (typically 3.5 t 4.5 percent by ttal weight) t prduce 25- t 35-percent vids in the mix after cnstructin. The pen-graded asphalt mixture can be prduced in a cnventinal batch plant r drum-mix plant. After placing, the pen-graded asphalt material is smthed ver with a minimal number f passes (usually 2 r 3) frm a small (3-tnne maximum) steel-wheel rller. (1) The resin mdified cement grut is cmpsed f fly ash, silica sand, cement, water, and a crss plymer resin additive. The resin additive is generally cmpsed f five parts water, tw parts plymer resin f styrene and butadiene, and ne part water-reducing agent. The grut water/cement (w/c) rati is

4 between 0.65 and 0.75, which prvides a very fluid cnsistency. The cement grut material can be prduced in a cnventinal cncrete batch plant r a small prtable mixer. After the asphalt mixture has cled, the grut is pured nt the pen-graded asphalt layer and squeegeed ver the surface. The grut is then vibrated int the vids with the 3-tnne vibratry steel-wheel rller t ensure full penetratin f the grut. This prcess f grut applicatin and vibratin cntinues until all vids are filled with grut. (2) Depending upn the specific traffic needs, the freshly gruted surface may be hand brmed r mechanically textured t imprve skid resistance. In mst circumstances, hwever, the excess grut is squeegeed ff f the pavement surface, and a natural rugh texture is achieved thrugh evapratin f surface bleed water. Spray-n curing cmpunds, typical t the PCC industry, are generally used fr shrt-term curing. The new RMP surfacing usually achieves full strength in 28 days, but it may be pened t pedestrian traffic in 24 hurs and light autmbile traffic in 3 days. c. Pavement Design. The pavement thickness fr the RMP is t be determined using flexible pavement criteria. The ttal pavement thickness fr a pavement structure including the RMP shuld be determined using TM 5)822)5 and TM 5)825)2. After the pavement thickness has been determined fr a particular lad and level f traffic, the tp 50 mm f the asphalt cncrete layer are t be replaced with 50 mm f the RMP. This is a cnservative design apprach, but pending the utcme f further research in this area, all RMP prjects shuld be designed as a cnventinal flexible pavement in this manner. (1) In rehabilitatin prjects such as verlays, the verlay pavement thickness shuld be determined t satisfy traffic and lad requirements. The minimum verlay thickness is 50 mm when using the RMP. If additinal thickness is required, the remaining pavement thickness underlying the RMP surface shuld cnsist f high-quality asphalt cncrete. (2) RMP has been successfully cnstructed as an verlay material ver rigid and flexible pavements as well as in riginal cnstructin. N transverse r lngitudinal jints are required fr riginal, full-depth RMP designs althugh jints have been cut in RMP when verlaying jinted PCC pavement. Cracking and seating f existing PCC and then verlaying with an AC interlayer and RMP surfacing has been a successful design apprach. Pavement jints are required between RMP and adjacent PCC pavements but are nt required between RMP and adjacent AC 2

5 pavements. These jints are cnstructed by saw cutting t the bttm f the RMP layer nce the RMP material has sufficiently cured. The jint is then filled with a sealant material suitable fr the particular site cnditins. (3) Mix design methdlgies fr RMP have nt been previusly dcumented. All RMP military cnstructin prjects t date have had Gvernment prvided mix designs, prvided by the U.S. Army Engineer Waterways Experiment Statin, CEWES-GP, Vicksburg, MS, The mix design methd fund in Appendix B prvides suitable jb-mix frmulatins fr bth the pen-graded asphalt cncrete and grut materials when designing an RMP. This mix design methd als cntains apprpriate prcedures fr quality cntrl testing f pen-graded AC vids and grut viscsity. d. Applicatins. RMP may be used in new pavement cnstructin r in the rehabilitatin f existing pavement structures. A new RMP surfacing may be placed as an verlay ver existing flexible r rigid pavements. RMP is typically used as a lw-cst alternative t a PCC rigid pavement r as a means f imprving the pavement perfrmance ver an AC surfaced flexible pavement. Field experience indicates that RMP may be used in practically any envirnmental cnditins. (1) In general, the RMP is best suited fr pavements that are subjected t lw-speed traffic that is channelized r abrasive by nature. Pavement areas with heavy static pint lads and heavy fuel spillage are als ideal RMP applicatin candidates. The practical limit fr the surface slpe f an RMP sectin is 2 percent. Pavement slpes up t 5 percent can be cnstructed, but excess hand wrk and grut verruns are t be expected with slpes greater than 2 percent. (2) The RMP prcess has been used in a variety f applicatins n the internatinal market, including airprt and vehicular pavements, industrial and warehuse flrings, fuel depts and cmmercial gasline statins, city plazas and malls, railway statins, and prt facilities. Since its first cmmercial applicatin in the United States in 1987, RMP has been used mstly n airprt and airfield pavement prjects. These applicatins have included taxiways, aprns, equipment and fuel strage areas, and warehuse parking lts. As f September 1996, there were 17 knwn RMP prject sites in the United States, ttaling ver 180,000 sq m (216,000 sq yd) f pavement area. e. Csts. The cst f a 50-mm-thick (2-in.) RMP layer is currently abut $9.60 t per sq m ($8 t 16 per sq yd) as 3

6 cmpared t a typical cst f $3.60 t 6.00 per sq m ($3 t 5 per sq yd) fr a 50-mm-thick (2-in.) layer f dense-graded asphalt cncrete. The initial cst f a full-depth RMP design is generally 50 t 80 percent higher than a cmparable asphalt cncrete design when cnsidering a heavy-duty pavement. A mre imprtant cst cmparisn is between the RMP design and the rigid pavement design since the RMP is usually used as a cst saving alternative t the standard PCC pavement. In the case f a standard military heavy-duty pavement applicatin~ the RMp design is generally 30 t 60 percent less in initial cst than a cmparable PCC pavement design. In many circumstances, the RI@ als prvides life cycle cst savings frm reduced r eliminated maintenance effrts when cmpared t flexible pavements and jinted rigid pavements. 5. ~. The enclsed mix design methd shuld be used fr determining jb-mix frmulatins relating t the cnstructin f RMP. Guidance n the use f RMP is available frm the U.S. Army Engineer Waterways Experiment Statin, 3909 Halls Ferry Rad~ CEWES-GP, Vicksburg, MS This letter will have rutine applicatin fr military cnstructin as defined in paragraph 6c, ER FOR THE DIRECTOR OF MILITARY PROGRAMS: 2 Appendices.E. APP A-References ing Divisin APP B-Resin Mdified Pavement Military Prgrams (RMP) Mix Design Methd 4

7 A-1. Required References. a. Engineer Regulatin. APPENDIX A: REFERENCES ER Design Plicy fr Military Cnstructin b. Technical Manuals. TM Engineering and Design f Flexible Pavements fr Rads, Streets, Walks, and Open Strage Areas TM /AFM 88-6 Flexible Pavement Design fr Airfields c. Crps f Engineers Guide Specificatin. CEGS Resin Mdified Pavement d. American Sciety fr Testing and Materials. ASTM C 127 Test Methd fr Specific Gravity and Absrptin f Carse Aggregate ASTM C 128 Test Methd fr Specific Gravity and Absrptin f Fine Aggregate ASTM C 136 Methd fr Sieve Analysis f Fine and Carse Aggregates ASTM D 70 Test Methd fr Specific Gravity and Density f Semi-Slid Bituminus Materials ASTM D 75 Practice fr Sampling Aggregates ASTM D 140 Practice fr Sampling Bituminus Materials A-1

8 A-2. Related References. TM /AFM 88-7 General Prvisins and Gemetric Design fr Rads, Streets, Walks, and Open Strage Areas TM /AFMAN General Prvisins fr Airfield/Heliprt Pavement Design Ahlrich and Andertn 1991 Ahlrich, R. C. and Andertn, G. L "Cnstructin and Evaluatin f Resin Mdified Pavement," Technical Reprt GL)91)13, U.S. Army Engineer Waterways Experiment Statin, Vicksburg, MS Andertn and Ahlrich 1994 Andertn, G. L. and Ahlrich. R. C "Design, Cnstructin, and Perfrmance f Resin Mdified Pavement at Frt Campbell Army Airfield, Kentucky," Technical Reprt GL-94-5, U.S. Army Engineer Waterways Experiment Statin, Vicksburg, MS Andertn 1996 Andertn, G. L "User's Guide: Resin Mdified Pavement," FEAP-UG-96/01, U.S. Army Center fr Public Wrks, Alexandria, VA A-2

9 APPENDIX B: RESIN MODIFIED PAVEMENT (RMP) MIX DESIGN METHOD B-1. Open-Graded Asphalt Cncrete. a. Preliminary. (1) Gather representative samples f aggregates and asphalt cement. Sample aggregates accrding t American Sciety fr Testing and Materials (ASTM) D 75 and asphalt cement accrding t ASTM D 140. An pen-graded asphalt cncrete mix design requires a minimum f 45 kg f each aggregate stckpile and 15 L f asphalt cement. (2) Oven dry aggregate stckpile samples and cnducts a sieve analysis (ASTM C 136) n each sample. Determine the cmbinatin f aggregate stckpiles that results in a gradatin clsest t the center f the limiting gradatin band specified in CEGS This stckpile cmbinatin will becme the blending frmula fr the pen-graded asphalt cncrete. (3) Ensure that the aggregates representing the selected stckpiles and the asphalt cement meet the quality requirements as detailed in CEGS Measure apparent specific gravity f aggregates (ASTM C 127 and C 128) frm each stckpile used in the final gradatin. Calculate apparent specific gravity f cmbined aggregates using the blending frmula percentages. Measure specific gravity f asphalt cement (ASTM D 70). (4) Estimate the ptimum asphalt cntent using the fllwing equatin: where " = 2.65/SG Optimum asphalt cntent = 3.25(")E 0.2 SG = apparent specific gravity f the cmbined aggregates E = cnventinal specific surface area = 0.21G + 5.4S s + 135f G = percentage f material retained n 4.75-mm sieve S = percentage f material passing 4.75-mm sieve and retained n 600-µm sieve B-1

10 s = percentage f material passing 600-µm sieve and retained n 75-µm sieve f = percentage f material passing 75-µm sieve (5) Rund the calculated ptimum asphalt cntent value t the nearest tenth f a percent. Use this asphalt cntent value alng with tw asphalt cntents abve this amunt and tw asphalt cntents belw this amunt in the prductin f mix design samples. Use 0.5 percent abve and belw the ptimum and 1.0 percent abve and belw the ptimum as the fur additinal asphalt cntents. Calculate maximum theretical specific gravities fr each f these five asphalt cement cntents. b. Specimen prductin. Using the five mix design asphalt cntents, prduce three 100-mm-diameter Marshall specimens at each asphalt cntent. Use apprximately 800 grams f cmbined aggregates fllwing the previusly determined aggregate blending frmula fr each specimen. Just befre mixing, the temperature f the aggregates shuld be C and the asphalt cement shuld be C. With nrmal mixing prcedures, the temperature f the asphalt mixture during cmpactin is C. Cmpact the pen-graded asphalt cncrete specimens with 25 blws frm a 4.5-kg Marshall hand hammer n ne side f each specimen. Allw the specimens t air cl fr a minimum f 4 hurs befre carefully remving frm mlds. c. Measuring vids ttal mix (VTM). (1) Measure the VTM f each pen-graded specimen using the fllwing frmula: where VTM = (1 - WT air/vlume * 1/SG T) * 100 Wt = dry weight f specimen air Vlume = B/4 D 2 H D = diameter H = height SG = maximum theretical specific gravity T (2) Calculate the average VTM fr each f the five asphalt cement cntents. Select the ptimum asphalt cntent as that B-2

11 which resulted in a VTM value clsest t 30.0 percent. If n VTM averages are in the 30.0 percent range, then slight adjustments t the aggregate gradatin may need t be made t achieve the prper vid cntent. Optimum asphalt cntents resulting in average VTM values in the 25 t 35 percent range are acceptable, but due t nrmal prductin and cnstructin variatins, a mix design that prvides a 30-percent VTM value is mst desirable. (Typical ptimum asphalt cntents are between 3.5 and 4.5 percent.) d. Jb-mix frmula. (1) The pen-graded asphalt cncrete jb-mix frmula will cnsist f the fllwing infrmatin: (a) Percentage f each aggregate stckpile. (b) Percentage passing each sieve size fr the blended aggregate. (c) Percentage f bitumen. (d) Temperature f discharged asphalt mixture. (e) Vids ttal mix percentage. (2) The target temperature f the asphalt mixture when it is discharged frm the mixing plant shuld be C. Select 120 C when ambient temperatures are relatively high and the haul distance frm the asphalt plant t the jb site is shrt. Select 125 C when either the haul distance is relatively lng r the ambient temperatures are relatively cl. Select 130 C when ambient temperatures are expected t be cl and the haul distance is relatively lng. Persistent high winds during cnstructin may als require mix prductin temperatures t be in the 125 C t 130 C range. B-2. Resin Mdified Prtland Cement Grut. a. Preliminary. (1) Gather representative samples f prtland cement, silica sand, Class F fly ash, and resin additive. Minimum sample sizes are 23 kg each f cement, sand, and fly ash, and 4 L f resin additive. Ensure that all materials meet the quality requirements as detailed in CEGS B-3

12 (2) Using the grut material prprtins specified in CEGS and shwn belw, develp a matrix f initial jb-mix frmulas fr labratry viscsity testing. The gal f the grut mix design is t prduce a material frmulatin which results in a Marsh Flw Cne viscsity f 8.0 t 10.0 secnds. The initial frmulatins shuld ensure that a grut frmulatin can be prduced with a Marsh viscsity n greater than the 10.0 secnds maximum. This is accmplished by testing grut frmulatins with relatively high w/c ratis and the maximum allwable amunt f resin additive. Typical initial grut frmulatins tested in a mix design evaluatin are shwn belw. Batch Percentage by Weight CEGS Material Limits Trial 1 Trial 2 Trial 3 Prtland Cement Silica Sand Fly Ash Water Resin Additive (3) Althugh the grut's w/c rati is unspecified, the desirable w/c range is 0.65 t Lwer w/c values are mre desirable t reduce the risk f shrinkage cracking and fr higher grut strengths. Higher w/c ratis are smetimes necessary t prduce gruts with Marsh Flw viscsities less than the 10.0-secnd maximum value. Therefre, the fcus f the initial grut viscsity tests is t determine the minimum W/C rati that will prduce a grut viscsity less than r equal t 10.0 secnds. It is imprtant t remember that the resin additive serves as a plasticizer which reduces grut viscsity while reducing the amunt f water required. (4) The standard labratry grut batch size shuld be in the 4,000- t 5,000-g range. Calculate the material batch weights based n the desired prprtins. Multiple grut viscsity tests are facilitated by first blending the dry ingredients (cement, sand, fly ash) fr each test sample and then adding the apprpriate amunt f water and resin additive during the mixing prcess. These dry- ingredient batches shuld be kept in air-tight cntainers t prevent lss f material r cntaminatin befre mixing. Tw replicate samples per blend are apprpriate fr grut viscsity testing. B-4

13 b. Mixing. ETL (1) The equipment needed t effectively mix the resin mdified pavement grut includes a labratry mixer equipped with a wire whip mixing attachment and apprximately 10-L-capacity mixing bwl, a calibrated set f weight scales, and varius small cntainers t weigh and transfer mix water and resin additive. (2) Place dry ingredients int mixing bwl and adjust the bwl height s that the wire whip is just ff f r tuching the bttm and sides f the bwl. Begin mixing the dry ingredients at a slw speed and immediately add the apprpriate amunt f water. Once all f the water is added, speed up the mixer t a pint where the grut is being thrwn nt the sides f the mixing bwl. Mix the grut at this high speed fr 5 minutes, then add the apprpriate amunt f resin additive. Mix the grut again at a high mixing speed fr an additinal 3 minutes befre testing fr Marsh Flw viscsity. c. Viscsity testing. (1) The equipment needed t measure grut viscsity includes a Marsh Flw Cne (Figure 1), a 1,000 ml glass r clear plastic graduated cylinder beaker, a 1,500 ml (apprximately) empty beaker r bucket, and a stpwatch. Have this equipment set up near the mixing bwl befre the end f the 8-minute grut mixing time. (2) Immediately after mixing the grut, transfer the grut frm the mixing bwl t the empty beaker r bucket. Take nte f any lumps f material r excess sand in the bttm f the mixing bwl. (Excess lumps indicate inadequate mixing and render the grut useless fr viscsity testing.) Immediately fill the Marsh Flw Cne with abut 1,100 ml f grut. (A cnsistent head f grut in the flw cne is achieved fr all viscsity tests by marking an 1,100 ml fill line inside the flw cne.) The flw cne utlet is plugged by simply placing ne's finger ver the utlet pening. Immediately after the flw cne is filled t te 1,100 ml fill line, psitin the cne ver the 1,000 ml graduated beaker. Release the grut pening and start the stpwatch timer simultaneusly. Measure the time f flw fr 1 L f grut frm the flw cne t the nearest tenth f a secnd. B-5

14 155 mm (6.2 In.) Inside Diameter mm (12.6 In.) 60 mm (2.4 In.) * I \IO mm (0.A In.) Inside Diameter Figure 1. Crss-sectin f Marsh Flw Cne (3) Recrd each test sample s viscsity, averaging the tw replicates fr each blend. Adjust the grut mix prprtins as needed with the fllwing cnsideratins: (a) Any grut viscsity between 8.0 and 10.0 secnds is acceptable. It shuld be nted, hwever, that when field cnstructin temperatures are expected t be cmparatively high (greater than 32 C) and/r the pen-graded asphalt cncrete vids are expected t be cnsiderably lw (less than 30 percent), then lwer viscsity gruts will help t ensure easy grut applicatin and full grut penetratin. In mst cases, these variables are unknwn; therefre, it is prudent t select the grut frmulatin which has the lwest viscsity. B-6

15 (b) It is best t develp a grut jb-mix frmula with water and resin additive cntents belw the maximum allwable limits t allw fr small additins f these ingredients in the field if necessary t meet viscsity requirements. (c) Lwer w/c ratis are mre desirable fr a number f reasns: they tend t prduce gruts f higher strengths; they reduce the chances fr drying shrinkage cracking; they prduce gruts which are mre cnsistent and better able t keep the sand in suspensin during mixing and placement. (d) When the sand is nted t settle ut f slutin during r immediately after mixing, it can be expected that similar prblems wuld ccur in the field during cnstructin. This prblem can be remedied by reducing the amunt f sand and increasing the amunt f fly ash (bth within the specified tlerances) t prduce a slightly creamier grut. (e) When it becmes impssible t meet the viscsity requirements within the specified limits fr material quantities, there usually is a prblem with a particular ingredient. Sme f these deficiencies are detectable, while thers are nt. These material deficiencies may include ne r mre f the fllwing: grut sand which is t carse, prtland cement which is highly reactive during the early stages f the hydratin prcess, fly ash with excess cementitius nature. When it is pssible t islate the prblem material in these instances, the nly recurse is t substitute anther material frm anther surce whse physical r chemical difference will likely slve the prblem. d. Jb-mix frmula. The grut jb-mix frmula will cnsist f the fllwing infrmatin: (1) Percentage (by weight) f each mixture ingredient runded t the nearest tenth f a percent. (2) Type and surce f prtland cement. (3) Surce f fly ash, silica sand, and resin additive. (4) Marsh Flw Cne viscsity f jb-mix-frmula grut. B-7