There is provided an apparatus (100) for manufacturing a cementitious slurry comprising foam, the apparatus (100) comprising: a mixing chamber (101) for mixing a cementitious material and water to form a cementitious slurry, a channel (103) fluidly connected to the mixing chamber (101) at a first end, the channel (103) for receiving the cementitious slurry from the mixing chamber (101), the channel (103) extending from the first end and terminating a second end; the channel (103) comprising a foam inlet (106) for introducing foam into the channel (103); wherein the portion of the channel (103) between the foam inlet (106) and the second end has a length from 400 mm to 1200 mm inclusive, wherein said foam inlet (106) is positioned such that the distance between said first end of said channel (103) and said foam inlet (106) is less than 25% of the distance between said first end of said channel (103) and said second end of said channel (103). A cementitious slurry channel (103) and a method of manufacturing a cementitious slurry are also provided.

A mixer (1) comprises a drum (2) having at least one inlet (6) and one outlet (7). The mixer (1) furthermore comprises a drive (3) and a stirring shaft (4), which is arranged in the drum (2) and is coupled to the drive (3). Furthermore, the mixer (1) comprises a conveying device (5), which is arranged in the drum (2) and which is arranged on one and the same axis as the stirring shaft (4).