Replies

1. 
   CapnMac | Jul 15, 2004 12:07am | #1

   The way I learned it, was you either used the aggregate already in the mix (wash off method), or you floated the slab then distributed retarder over the surface so you could set stone into the cream (applied method).

   Applying the exposed "aggregate" has some distinct advantages.  First off, you get to screed to known dimensions (and you are not creating runoff that may (right) soon become regulated).

   In my part of Texas, the cheaper aggregate is crushed stone, so it's more expensive to use water-washed stone for the whole batch.  Whereas I can get a short load of stone, and to customer spec for color, shape, and size, to apply over prepared concrete.

   That's my bias, though.

   Occupational hazard of my occupation not being around (sorry Bubba)
1. 
   brownbagg | Jul 15, 2004 01:27am | #2

   another way is to place regular concrete and then broadcast a wash river rock or pea gravel on top just before setting.

1. 
   CapnMac | Jul 15, 2004 10:47pm | #5

   That's my "applied" method, in case it wasn't clear.  The hardest part, is getting it to float back after broadcast.  Takes a deft hand (or just one less ham-fisted than mine) and some patience.Occupational hazard of my occupation not being around (sorry Bubba)

2. 
   Jessex | Jul 15, 2004 03:06am | #3

   I am doing a slab with exposed edges so am using a "wash off" method. But not sure how much aggregate to include.

   Jesse

1. 
   Isamemon | Jul 15, 2004 03:47am | #4

   so lots of mud workers who will rip on me for this

   because I ma sure there is a better way............................

   after your last float spray a solution of sugar and water over the mud. 1 to 4 ratio

   wait a while ( depends on heat and all of that)

   hose it off

   why the sugar works as good as big dollar retarder I dont know

   this trick was taught to me by an old flatworker who said it he was taught to him  by a Chicagao union boss to save money

   for best results the best way is to notify the yard that you are doing exposed ag

   then they put in mostly small river rock

   but we have done this with just palin old crushed 3/4-

   havent done it for an inteior job, only sidewalks, porches etc.

   side note

   I dont care what method  you use

   but I have had many people tell me that biggest problem with exposed ag is that water  collects easy, and in winter water turns to ice/ that an exposed ag is great until it frezzes over and then is worse then a regular broom finish side walk

   just a thought

   Edited 7/14/2004 8:49 pm ET by hammertime

2. 
   CapnMac | Jul 15, 2004 10:58pm | #6

   If you are washing off, the best way is to use whatever size aggregate you want exposed in the whole batch.  So, if you want 3/8 river rock exposed, use that in the mix.  So, the aggregate volume is the same, the sizing changes, that's all.

   I checked with my concrete guy last night.  He likes to use an accellerant in the mix, to get the body to set.  Then, after floating, using a retarder on the cream (just broadcast over the surface).  His experience is that lets you use a hose (at low pressure) and a broom to get the surface uniform.  His other recommendation was to short the water in the mix by about 5%, too.Occupational hazard of my occupation not being around (sorry Bubba)

1. 
   Jessex | Jul 16, 2004 12:12am | #7

   Tx for the information. Much appreciated.

   Jess