Disclosed is a foam modifier, e.g., useful for gypsum or cement slurries. The foam modifier comprises a fatty alcohol that is added to a gypsum or cement slurry that includes foaming agent, such as an alkyl sulfate surfactant. The fatty alcohol can be a C.sub.6-C.sub.16 fatty alcohol in some embodiments. The use of such a foam modifier can be used, for example, to stabilize the foam, reduce waste of foaming agent, improve void size control in the final product, and improve the gypsum board manufacturing process.

An efficient sound-absorbing lightweight aggregate cellular concrete, a method for preparing the same, and an application thereof. The concrete comprises: 85-95 parts by weight of low-carbon sulfur-aluminum-ferric cementitious materials, 5-15 parts by weight of supplementary cementitious material, 0.6-1.5 parts by weight of functional admixture, 20-60 parts by weight of non-sintered lightweight aggregate, 0.35-0.45 parts by weight of water, and 0.5-1.5 L of preformed foam. The non-sintered lightweight aggregate includes cementitious materials, byproduct gypsum, hydrogen peroxide, water, and expanded perlite. A multi-level pore structure is constructed from expanded perlite pores, hydrogen peroxide foaming pores, and physical foaming pores. The material exhibits a noise reduction coefficient 0.80, a bulk density500 kg/m.sup.3, and a flexural strength 1.5 MPa.

Perlite-free, lightweight setting-type joint compounds which comprise calcium sulfate hemihydrate with a dry density of less than 50 lb/ft.sup.3, a foaming agent having a HLB value of at least 10 and preferably comprising an alkylbenzene sulfonic acid having a linear alkyl chain containing 8 to 14 carbons and/or a salt thereof, and a combination of rheology modifiers. Methods for building wallboard assemblies and methods for wall patch and repair projects that include applying the perlite-free, lightweight setting-type joint compounds to a substrate.