• Home
  • Download PDF
  • Order CD-ROM
  • Order in Print
JOB-MIX FORMULA (AC MIXES)
CHAPTER  18 SOIL STABILIZATION - 14070_423

Engineering Aid 1 - Advanced Structural engineering guide book
Page Navigation
  393    394    395    396    397  398  399    400    401    402    403  
the  binder.  The  procedures  follow  those  used  for hot-mix design (Marshall method), in general, with the following    modifications: .  Aggregates.  Aggregates should be dried to a moisture content expected during construction (up to a maximum of 2 percent, by weight). .   Asphalt.   Mix   selected   bitumen   with   the aggregates, but at the temperature recommended for field  application.  The  aggregates  remain  at  room temperature. . Curing. Before compaction, cure the mixture for at least 12 hours in an oven set at 140°F (  + 5°). l Cooling. After molding, cool the specimens to room temperature in the molds. You must take care to remove the specimens, undisturbed and undamaged, from the molds. . Testing. Heat the specimens in an oven to 100° ( + 2°) and test them in the Marshall machine. Heating will normally take about 2 hours. l Selection of the design amount of asphalt. The asphalt contents at maximum density and maximum stability, after averaging, are used as the design amount. SURFACE AREA METHOD OF MIX DESIGN When   laboratory   equipment,   except   for   sieve analysis,  is  not  available,  the  following  formulas  may be used in place of laboratory procedures to determine the  necessary  asphalt  content: 1. where: P   = a = For  asphalt  cement: P  =  0.02a  +  0.07b  + 0.15c   +   0.20d percent (expressed as a whole number) of asphalt  material  by weight of dry aggregate percent (expressed as a whole number) of mineral aggregate retained on the No. 50 sieve percent (expressed as a whole number) of mineral aggregate passing the No. 50 and retained on the No. 100 sieve percent (expressed as a whole number) of mineral aggregate passing the No. 100 and retained on the No. 200 sieve d    = percent  (expressed  as  a  whole  number)  of mineral aggregate passing the No. 200 sieve Absorptive  aggregates,  such  as  slag,  limerock,  vesicular lava,  and  coral,  will  require  additional  asphalt. 2. where: P   = A   = B   = C   = Q1. b    = c = 17-22 For  asphalt  emulsion: P = 0.05  A + 0.1 B + percent  (expressed  as 0.5 C a whole number) by weight of asphalt emulsion, based on weight of graded mineral aggregate percent (expressed as a whole number) of mineral aggregate retained on the No. 8 sieve percent (expressed as a whole number) of mineral aggregate passing the No. 8 sieve and retained on the No. 200 sieve percent (expressed as a whole number) of mineral aggregate passing the No. 200 sieve QUESTIONS Your  battalion  has  been  tasked  to  replace  a 5-inch-thick  2,000-square-yard  reinforced concrete parking lot located at a naval air facility in northern Japan (extreme exposure). Your job is to design a concrete mix and determine the total quantities of materials needed to complete the project. Based on the parameters listed below, what  is  the  (a)  maximum  size  of  the  coarse aggregate  that  you  should  use,  (b)  amount  of water (in gallons) needed for a 1-cubic-yard trial batch (c) amount of sand (in pounds) needed for a 1-cubic-yard trial batch (d) number of sacks of Type IA cement needed for the project, and (e) the amount (in tons) of coarse aggregate needed for the project? Average  28-day  compressive  strength (based on flexural-design strength) Fineness modulus of fine aggregate Specific gravity of portland cement Specific gravity offine aggregate Specific gravity of coarse aggregate Dry-rodded weight of coarse aggregate Dry-rodded  weight  of  fine  aggregate Slump 3,500 psi 2.6 3.15 2.75 2.65 110 lb/cu ft 100 lb/cu ft 2 in







Western Governors University

Privacy Statement
Press Release
Contact

© Copyright Integrated Publishing, Inc.. All Rights Reserved. Design by Strategico.