Granite powder (GP) alkaline waste of industrial origin that can provide nutrients for agricultural production. However, due to its high alkalinity it can reduce the availability of Fe and generate chlorosis in plants. In this work, the use of geomimetic composites mixed with GP has been proposed as an eco-friendly plant growth substrate. Thus, bentonite-poly(glycerol citrate) geomimetic composites (BPGC) were synthesized and added to GP. The effect on nutrient leaching, growth of Lolium perenne and physicochemical properties of substrates prepared were assessed. BPGC were synthesized by surface modification of bentonite with (3-aminopropyl) triethoxysilane and followed by polyesterification with glycerol and citric acid. Structural characterization by infrared spectroscopy, magnetic resonance and scanning electron microscopy allowed to verify that structural configuration mimics the structure of soil particles. BPGC showed a thermal degradation from similar to 140 degrees C and a decrease on Tg as clay content in composite is increased. Leaching profiles of substrates produced from GP and BPGC showed the ability of mixture to interact with nutrients and reduce the losses of them, showing a greater tendency for retaining of potassium and phosphorus. Finally, the plant growth experiments showed no trend or relationship between the yield of Lolium perenne and the treatments assayed. Therefore, it is concluded that the addition of BPGC to GP modulated and improved the physicochemical properties of the substrates evidencing its potential application as amendment for the restoration of degraded soils, however, an improvement in the growth of the plants evaluated was not evident.
Granite powder, a byproduct of granite quarrying, enhances the long-term strength of cement-treated soil due to its pozzolanic reactivity. However, its effects on early strength and seawater durability, as well as its influence on slag-treated soils, remain unexplored. We studied cement-treated and slag-treated soil composites with 0 % and 30 % granite powder, using 8 % cement or 30 % steel slag per dry soil mass. We performed vane shear and unconfined compressive strength (UCS) tests at 1, 3, 6, 12 hours, and 1, 3, 7, 28, 63, 91, 119 days. After 28 days of air curing, samples endured seawater exposure at 30 degrees C for 0, 28, 63, and 91 days, followed by UCS and XRF calcium composition tests. Seawater samples were also analyzed for calcium and magnesium concentrations using a photometer. Despite similar dry unit weights, slag-treated soil initially exhibited lower strength than cement-treated soil. However, granite powder enabled slag-treated samples to reach comparable strength levels to those of cement-treated soil. Its pozzolanic reactivity facilitated self-repair in samples affected by seawaterinduced calcium depletion, while also reducing emissions, resource consumption, and construction costs associated with treated soil materials.
An experimental study was undertaken to investigate the effect of plastic and granite waste powder on the geotechnical performance of expansive soil, using different mix ratios. The soil studied is Hachem, in the northwest of Algeria. In this context, reinforce the plastic powder with granite powder, then add the mixture to the expansive soil. The percentage of plastic powder is (0%, 1%, 2%, 3%, 4%) and reinforced at 2%, 4%, 6% and 8% with granite powder. The experimental results showed a gradual decrease in liquid limits, swell potentials, and swelling pressure as plastic and granite powder proportions increased. In terms of the results obtained by reducing swelling and swelling pressure values and increasing unconfined compressive strength (UCS) tests and ductility values, this mixture of waste plastics and granite can be of great importance in improving the mechanical properties of samples.