For the C-LWA dry, no extra water was added, hence the C-LWA reduced the effective w/c of the concrete mix by absorbing a part of the mixing water. The effective w/c thus dropped from the initial 0.55 to 0.42 due to C-LWA absorption, with further reduction down to 0.40 due to absorption by normal-weight aggregates. Even though the mix with C-LWA dry was based on the same design as the reference concrete, the absorption of a part of the mixing water led to a reduction of the concrete volume from the original nominal 1 m 3 . Hence, the quantities of all components were scaled up to reach the nominal volume of 1 m 3 (see Table ).