Investigation on alkalinity reduction methods of eco‐porous concrete

Abstract

Laboratory tests were conducted to investigate the different alkalinity reduction methods. Single alkalinity‐reduced treatment and hybrid alkalinity‐reduced method were employed respectively. Single alkalinity‐reduced treatment methods include oxalic acid soaking, oxalic acid spraying and deep penetrating sealer (DPS) spraying. The hybrid alkalinity‐reduced method used silica fume (SF) and ferrous sulfate. Deep penetrating sealer spraying and rapid carbonization were performed in the hybrid alkalinity‐reduced treatment. The compressive strength and alkalinity of eco‐porous concrete were evaluated by employing different alkalinity‐reduced methods. The results showed that effect of single alkalinity‐reduced treatment on the strength of eco‐porous concrete is not obvious. The 28‐day compressive strength of the specimens was 7.8 MPa ‐ 10.3 MPa and the pH value was about 10.4. By using hybrid alkalinity‐reduced method, the rapid carbonization and alkali solidification gave the best performance in strength and alkalinity reduction. The 28‐day compressive strength was 8.1 MPa and pH value was reduced to 10.0.

Research and Application Progress of Vegetation Porous Concrete

“…High-efficiency water reducers [9][10][11][12] are used to enhance the fluidity of cement slurries, making it easier for the cement slurry to encapsulate the aggregates. Yang [48] soaked and sprayed vegetation porous concrete with oxalic acid, which effectively lowered the pH of the vegetation porous concrete. However, compared to spraying, soaking significantly reduced the mechanical strength of the vegetation porous concrete.…”

“…While this approach can reduce alkalinity, it has a significant impact on the mechanical and durability properties of the concrete [78], and its application during construction can be challenging; 4. Selecting the addition of chemical admixtures, which has proven to be efficient [8,[48][49][50][51][52][53][54]. However, environmental impacts, durability, higher costs, research, regulation, and monitoring are important considerations and challenges associated with this method.…”

“…Selecting the addition of chemical admixtures, which has proven to be efficient [8,[48][49][50][51][52][53][54]. However, environmental impacts, durability, higher costs, research, regulation, and monitoring are important considerations and challenges associated with this method.…”

Study on Alkali Reduction Treatments and Plant Growth Properties of Planting Concrete

“…Kong et al [16] used waste oyster shells as inert filler to fabricate porous concrete, discovering that the pH values could thereby be reduced to 8.52. Recently, the methods of alkalinity reduction mainly include the modification of the planting substrate [17], carbonization [18], and chemical treatment [19]. There are some further studies concerning the alkalinity reduction methods needed to obtain the required properties of PC.…”