Natural Sand Vrs Man ufactured Sand
We are in an area that in the past used natural sand for all concrete mixes. We all know the times have changed. My q uestion is, how do we educate the pum p owners and operators in our area that manufactured sand is the future?
They claim that it will not pump, and it wears the unit out much faster than nat ural sand. We also have discovered the y are priming the pump with the concret e mix.
I would like to hear from other concrete suppliers and pump manufactures on t he pumping of manufactured sand. Is it a wide spread problem?
It's only a matter of time before the pu mping guys will have 2 choices Pay a premium for concrete made with natural sand or ; Pay for add mixtures and the additional wear costs
Pumping concrete with manufactured s and increases the pumping pressure a nd causes additional wear/tear on equi pment. But t the more organic issue is t he ability to accept the change.
To manufactured sand mix designs pu mp, place, and finish just fine. The chall enge is in proper proportioning (just like any concrete mix design) and the abilit y of the finisher to accept those change s.
While it is true that rounded particles sh ould pump well than angular particles d o, many natural sands available to our r egion have very little on the 0.15mm, a nd 0.3mm.
The manufactured sands we use provid e the missing fines that not only assist pumping but also finishing. Where poss ible, we blend both sands for the best o f both worlds.
We are also fortunate to have a depart ment of transport that recognizes a fine r grading that benefits all parties. The d epartment of transport passing spec is 15-20% for the 0.3 mm and 8-22% for t he 0.15 mm.
Degussa Admixtures has actually creat ed a Liquid Sand Program that has hel ped producers and contractors through out the nation to overcome the problem s associated with the use of manufactu red sand in concrete.
This Liquid Sand Program involves the use of a unique VMA (Viscosity Modifyi ng Admixture) that lubricates the concr ete mix to make it easier to pump, plac e, and finish.
This means reduced pump pressures, l ess wear and tear on equipment, and l ess work to finish the surface. The VMA also helps to control excess bleeding, which can be an issue with the use of manufactured sand.
Yuleba Minerals ( www.yulebaminerals.com.au ) produce s a natural sand with full grading which is available throughout Roma, Miles, C hinchilla and the Southern Queensland.