There are several things that cause spalding one of them is called hot concrete, now what that means is the cement paste itself is of a low grade which means the past is used green and not had time to cool down. Now when mixed to become concrete and placed the surface will be tacky and pull on the float which means in part that the concrete is at a high temperature (hot) and is not been given a chance to cool properly and Hydrate so. Now in order for that concrete not to be hot it must be cooled, so if the material house that brought you the mix had the curtousy to tell you that it was a low grade paste (cement) one of two things would happen,one you would say do not bring it or two put ice in the mix which would cost around another fifty dollars a yard and of course there is always three and that being the job surface may pit anyway. So the bottom line here is do you want a low grade cement on your job as for myself I would not do either, unless the client was informed of the situtation with the cement. Usually the only time there is low grade cement is during a shortage of which happened in the 70's and with a bad winter to boot that is exactly what happened to concrete surfaces and not one manufacturer or material house told any contractors and thousands of jobs went bad from spalding. You want to be sick, how would you like to be in the business and have twenty or thirty jobs spald and every customer pointing the finger at you when the real falt was the cement being manufactured in low grade and being past on down to you as high quality. We have the same problem now as in the 70's and again the contractors are getting together on their own, because these manufaturers and material houses are hurting our individual reputations, yes we are all compeditive with each other in the quality of our workmanship and all take great pride in it, most of us in a given area all know eachother and respect eachother and we are all individuals,yet we come together in situations like this.