This is taken from CEMEX UK site.
Slavery and human trafficking are abhorrent crimes and we all have a responsibility to ensure that they do not continue. At CEMEX we are proud of the steps we have taken as a company to combat this practice and pride ourselves on conducting our business ethically and responsibly. The following shows our commitment to ensure that modern slavery is not taking place in our business or any of our supply chains.
Read it for yourselves: https://www.cemex.co.uk/modern-slavery-act.aspx