the generation of the waste depends on these items:

type of project, what is it for? residential, office, ....

type of materials that it will built by: concrete, wood or steel...

the environmental condition, is it warm, cold or...

the time of construction

and many other parameters , so it is better to clarify all items first

Good evening

I would suggest that you familiarise with the work of WRAP in the UK:

http://www.wrap.org.uk/category/sector/construction

and their MeasuRe tool:

http://measurebuiltenvironment.wrap.org.uk/

As well as information on Site Waste Management Plan which is required on projects over GBP300,000 in constructiion value in the UK.:

http://www.netregs.org.uk/pdf/SWMP_simple_guide.pdf

http://www.sitewastemanagementplan.com/

Be mindful of the differences in building construction techniques between the countries.

With best wishes

Vladimir

Effective management leads to low waste in construction.

It depends on topographical condition,Climatic Conditions , Materials used and Method of construction

You are non specific with regard to construction materials.  However, you question implies ready mix concrete.  The answer will be predicated upon variuos factors.  Depending upon the size of the project, the dimensions of the project, the vertical and horizontal footprint of the project, and the assumption that the delivery mode of the ready mix slurry will be pumped.  At the inception of a placement event, it will take anywhere from half a yard to charge a pump and up to anywhere from another half yard to three yards to wet out the hose and get it calbrated for proper placement.

Also, this will be a function of the diameter of the delivery hose, delivery distance, temperture.  If the concrete placement is being performed in hot weather, with the delivery hose in the hot sun, if there is a work stoppage, the contractor may have to purge his hose and reload with fresh material to keep concrete from setting up in the delivery hose.

If it is a large project, there can be a mutiplicity of pumping operaations.  

To answer your question, if the contractor can have a continuous pumping operation, a again, it will take half a yard to three yards to charge the system.  At least the same amount of slurry mass to discharge while cleaning, an indeterminate amount of water and generally associated chemicals to clean the pump, the hose or hose sections.

Sydney, this might be a long shot, but a colleague at Brigham Young, Jay Christofferson, has written a book on Excel modelling for builders.  It is called "Estimating with Microsoft Excel"...here is the Amazon link:

https://www.amazon.com/Estimating-Microsoft-Excel-3rd-Christofferson/dp/086718647X/ref=sr_1_1?ie=UTF8&qid=1468419251&sr=8-1&keywords=jay+christofferson

It might have some info on waste estimatiion in there as a forecasting model.

Well, there have been extensive researches carried out in estimating construction waste. Basically, there are two ways in doing this. One way is based on building types, in which the existing construction projects are divided into several types, such as residential (landed or high-rise), commercial, infrastructure etc. The amount of waste generated (either in tonne or kg) is divided by Gross Floor Area to obtain kg/m2 or tonne/m2. This figure is then to be used as guidance for waste estimation for any new construction project, as long as the size of the building is confirmed.

The another way of estimating construction waste is to by knowing the amount of materials used in the construction project. Researches show that about 5 to 10% of the construction materials may eventually turned into waste during the construction process. In this case, developing a list of construction material wastage level is of necessity. Such list can be obtained from previous study or to be compiled by the researcher him/herself. 

Please keep in mind that you may need a list of conversion factor (density) to facilitate you in calculation. Most of the time, the field record kept by the builders is in tonnage, but you may need those figure in mass. In this case, the list published by WRAP might be helpful to you.

It depends on variety of factors such as; material you use, method of construction, climate status of job site, time of construction and so on. 

I recommend checking this out.

https://www.wbdg.org/resources/cwmgmt.php

Every project (buildings, roads, bridges, etc.) consists of construction items. Each item has its own unit cost. The analysis of unit costs includes materials, labor, machinery, small tools and then general business expenses, profits, taxes.

If you analyze the materials of each item, you will find that in the calculations it is common to use more than 100% of each material considering possible losses. A first way to estimate the waste in a construction, is to calculate the excess of materials a constructor proposed to use, considering the losses, by comparing those numbers to the theoretical quantities. Then, during construction, adjustments should be done to each item