how to get black cement with pigment

[pokerkid]

I am doing some black sand wash (sai laang). The shop where i bought everything told me to mix the small stones (all black)  with 1 bag of tiger cement and 1 kilo of black pigment powder. is that all there is to it to get the black colour? 

[carlyai]

Hi, sorry but not sure on the shade of black colour that you will get, but I do no that many sai lang that I have seen (my own driveway as well), looks great to start with and then seems to crack. The sai lang coat seems to crack, not the concrete foundation.

 

Lately I have been using that green label cement (evidently pure cement, but not sure), or that white cement, on another project. These two types seem very strong and would probably stop the sai lang from cracking, but again not sure.

 

Maybe you have done this or you know what you are doing, but I would try and find some sai lang that has been down for over 2 years, and still looks good and find out what mix they used, as it does seem to get cracky and patchy after a couple of years.

[manfredtillmann]

black surfaces suffer from very large thermal expansion / contraction. you will get lots of cracking, no matter what materials you use. not a good choice in tropical countries (or anywhere else, for that matter).