Investigation of the Porosity Distribution, Permeability, and Mechanical Performance of Pervious Concretes

Abstract

Pervious concrete is a kind of porous and permeable material for pavements and slope protection projects, etc. In this paper, a kind of pervious concrete was prepared with Portland cement, silica fume (SF), polycarboxylate superplasticizer (SP), and limestone aggregates. The performance of concrete, such as its porosity, pore distribution, permeability coefficients, and mechanical properties, were studied through laboratory tests. The volumetric porosity was measured by the water displacement method, and the planar porosity and pore size distribution were determined using image processing technology. A permeameter with a transparent sidewall and an exact sidewall sealing method were used to measure the permeability coefficients accurately. The results show that the segregation index and flow values of pastes increased with the increase of SP and water cement ratio (W/C). The measured porosity (volumetric porosity and planar porosity) of pervious concrete with a single-size aggregate was closer to the design porosity than that with the blended aggregate. Compared with the design porosity selected in this study, aggregate size was the main factor influencing the pore distribution of pervious concrete. The standard deviation of the permeability coefficient was less than 0.03 under different hydraulic gradients. It was found that the relationships between the permeability coefficient and volumetric porosity (or effective pore size d 50 ) approximately obey polynomial function. Based on the test results, the optimized parameters were suggested for practical engineering: W/C of 0.26-0.30; 0.5% SP content; 5% SF content; 15-21% design porosity; and aggregate sizes of 4.75-9.5 mm and 9.5-16 mm.

Investigation of Particle-Related Clogging of Sustainable Concrete Pavements

“…It can be seen that the specimens with higher nominal maximum aggregate size (NMAS) had a higher proportion of large pores, whereas the specimens with lower NMAS had a relatively large percentage of small pores. This agrees with the findings of other studies related to image analysis of pore structure of porous materials [27,31].…”

“…A nonlinear equation was adopted in permeability calculations as it has been observed by some authors [29][30][31][32] to produce an excellent fit when used to evaluate the permeability characteristics of highly pervious coarse-grained materials. The relationship in this equation is expressed as…”

Laboratory Evaluation of Eco-Friendly Pervious Concrete Pavement Material Containing Silica Fume

“…At the beginning of the 21st century, pervious concrete regained the attention of researchers and engineers due to the emergence of various urban problems, such as urban floods, urban heat island effects, groundwater decline, etc. [4,[9][10][11][12]. Compared with traditional concrete, pervious concrete, as a porous material with high porosity, has great advantages [13][14][15][16].…”

Експериментальне Дослідження Стоку З Водопроникного Бетонного Покриття Для Високоінтенсивних Дощів Малої Тривалості

“…(Lin et al, 2014). Використання ВУП дає змогу зменшити об'єм поверхневого стоку мінімум на 40 %, забезпечує його часткове очищення, сприяє поповненню запасів ґрунтових вод, а також зниженню рівня шуму на дорогах (Alsubih et al, 2016;Liu et al, 2018;Luo et al, 2018;Pilon et al, 2019).…”

“…Гідравлічні дослідження підтверджують високий рівень водопроникності пористих бетонів. Значення коефіцієнта фільтрації, залежно від пористості матеріалу, розмірів заповнювача, густини та інших кількісних та якісних характеристик бетону, змінюється в межах 1-23 мм/с (Ali et al, 2014;Bean et al, 2007;Liu et al, 2018;Luo et al, 2018). Накопичення дощового стоку на поверхні ВУП можливе лише у випадках дуже коротких притоків високої інтенсивності (Zhuk & Kachmar, 2015 Регулювання дощового стоку за допомогою ВУПце достатньо глибоко вивчена на сьогодні проблема (Alyaseri & Zhou, 2015;Turco et al, 2017).…”