Showing papers on "Pervious concrete published in 1984"
Journal Article•
TL;DR: In this paper, different methods of improving sound-absorptive properties of porous concrete-based materials were investigated including: changing the material composition and thickness, incorporating resonator cavities in the form of resonator tubes or Helmholtz resonators, and sealing one face of homogeneous materials.
Abstract: Different methods of improving sound-absorptive properties of porous concrete-based materials were investigated including: (a) changing the material composition and thickness, (b) incorporating resonator cavities in the form of resonator tubes or Helmholtz resonators, and (c) sealing one face of homogeneous materials. The investigation encompasses both analytical analyses and laboratory measurements using both the impedance tube and the reverberation room measurement methods. The results indicate that one of the most promising methods to improve sound-absorption quality of porous concrete-based material is sealing one face of the material
2 citations
Patent•
09 Aug 1984
TL;DR: In this paper, the authors proposed the use of additives which improve the bonding action of the cement paste, such as highly disperse silica or a plastics dispersion having a proportion by weight of at least 1.5%.
Abstract: During the placing of fresh pervious concrete under water by means of an underwater concreting pipe, water already flows through the fresh pervious concrete, cement paste thus being washed out. This washing-out is avoided according to the invention by the addition of additives which improve the bonding action of the cement paste, such as highly disperse silica or a plastics dispersion having a proportion by weight of at least 1.5% of the cement weight.
1 citations