huangyhg

soff-cut saws for sawing slabs on grade
has anyone used a soff-cut saw for sawing slabs on grade? while it is propietary it has some things i like in that sawing can be done within 1-2 hours after placement, cuts dry without water, and due to rotation of blade minimizes raveling. i don't know how many of you are sick of hearing from the contractor he is not going to saw the slab until first thing in the mourning after placing the preceding mourning and then by the time they do get around to sawing the shrinckage cracks have already developed especially in hot weather. here is site for your information, however i want to hear good or bad as i am not promoting this manufacturer and i am sure others will follow suit if is is worthwhile.
i worked for an engineer in australia that specialised in industrial buildings. they specify that the sawn joints for all their slabs on ground are to be soffcut.
you should also use doweled joint every 3rd or 4th joint and pour strips along the sides.
our specification required the contractors bidding our jobs to use soff-cut for sawing contraction joints. if they don't have it, they can rent it.
we have it in the specs, but not by name. i don't recall the exact verbiage, but it basically forces them to use soff-cut. most of the contractors in the area now have it, so it's not the issue it used to be.
it is used every day for residential slabs. even with the blade/process specified, the concrete mix and specifications have to be designed for it to be used at the proper time.
if you use anything to retard the concrete curing (fly ash, etc.) you may put the proper sawing time out beyond a reasonable period if the weather is cool and moist. then, you will have to note the time period in the specifications for it to be reasonably enforced.
the most important thing is to make the depth of the cut about 1/3 of the slab thickness. obviously, reinforcement will have an effect and can overcome sawing.
dick
i specify the soff-cut saw joints on my foundation plans and details for slabs-on-grade. if a contractor doesn't want to saw it at the proper time, he is responsible for the cracking that occurs wherever the owner doesn't want the cracks. if the contractor does it as i specified, it's my problem. generally, i don't get resistance to the saw-cutting with the soff cut. i get resistance to proper curing.

__________________
借用达朗贝尔的名言：前进吧，你会得到信心!
[url="http://www.dimcax.com"]几何尺寸与公差标准[/url]