Using Waste Vermiculite and Dolomite as Eco-Friendly Additives for Improving the Performance of Porous Concrete

Abstract

The present study investigated the applicability of waste vermiculite and dolomite as fine aggregate, known as appropriate mineral adsorbents to enhance the quality of urban runoff, for improving the mechanical properties of porous concrete. 180 samples were mixed by adding 5-30% vermiculite and dolomite, as fine aggregate, and combining them with ordinary sand; lime sand (combining of 5-15% of each). Results showed that although adding dolomite culminated in a minor reduction of permeability-average of about 30%-, the average of compressive strength was augmented by 120%. Results of compressive strength of dolomite samples were repeated in mixtures containing vermiculite (an increase of 57%). While exploiting vermiculite in high percentages (20, 25, and 30) resulted in an extensive decrease in the permeability (94%), it was improved to an acceptable level (about 40%) after using vermiculite in combination with ordinary sand (lime sand). All dolomite and improved vermiculite mixtures, after combining vermiculite with ordinary sand, had appropriate performance in draining storm-urban runoff; such that in the weakest case, stimulated storm runoffs with heights of 10, 20, 30 and 40 cm were completely drained only after 17, 36, 59 and 87 seconds, respectively. Also, using vermiculite resulted in reducing the concrete weight (about 100 kg). Generally, although a little reduction in the permeability was seen, but using waste vermiculite and dolomite improved the mechanical properties of porous concrete significantly.

Enhancing Compressive Strength of Pervious Concrete for Use as Pavement Layer in Urban Roads Aper

“…Dolomitic rock has high surfaced hardness as well as density, it also has low water demand which is of benefit since Pervious Concrete has limited water. [14,15] studies indicated improvement in compressive strength due to the dolomitic rock's high resistance to abrasion and to attrition another study indicated using Pervious Concrete with dolomitic rock as coarse aggregates resulted in improved durability and long-term performance in comparison to with other types of aggregates and it requires less energy to produce compared to other types of aggregates. Gauteng Province has 25% of its land covered in dolomitic rock [16], with upgrading, extensions and new infrastructure on the rise and this type of aggregates being locally discarded material due the risk related to foundation problems and groundwater, makes dolomitic rock very affordable.…”

“…To determine the impact of compaction, samples were cast with and without compaction on the 3 sets of coarse aggregate sizes (7.1mm, 9.5mm and 19mm) dolomite rock. Different energies were administered in 3 layers (15,20,25) blows. Compacting Pervious Concrete is discouraged however there have been studies that found improved strength with minimum compaction.…”

Runoff Purification Effects of Permeable Concrete Modified by Diatomite and Zeolite Powder

“…(1) e evaluation indexes include effective porosity, compressive strength, and general purification effect. e optimal value of each evaluation index is selected as the reference sequence (Y 0 ), as shown in equation (5). e results are shown in Table 7:…”

“…Permeable concrete has many applications, such as a base for terraces and greenhouses on pavements, as well as reducing flow during floods and improving flow in road drainage. In addition, it is helpful for the recharge of groundwater resources [4][5][6][7][8][9][10][11].…”