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Density and water absorption coefficient of sandcrete blocks produced with waste paper ash as partial replacement of cement

Ekong Sylvester Andrew, Oyegoke David Adeniran, Edema Abayomi Ayodeji, Robert Ubong Williams

Advances in Materials Science

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2022

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Vol. 22, nr 4(74)

85--97

EN

The literature is flooded with scientific information on most durability properties except water absorption coefficient of masonry units like sandcrete blocks. Also, while waste papers disposal is a systemic problem due to ineffectiveness of waste management system in developing countries, the price of cement is on the increase. This situation, ultimately, causes a bane in achievement of low-cost housing development considering the fact that sandcrete blocks are predominantly used as walling elements for such undertakings. In this study, solid core sandcrete blocks were produced with waste paper ash (WPA) utilized as partial replacement of cement at 5 % and 10 % volumetric levels. Chemically, the WPA was found to show similarity with cement in terms of SiO2, Al2O3, and CaO contents. Density and water absorption coefficient of the block samples were determined. While density ranged from 1682 to 1872 kg/m3, water absorption coefficient varied from 27.04 to 23.49 kg/m2h0.5. Statistically, no significant difference was revealed at 𝑝<0.05 between experimentally-measured water absorption coefficients and those obtained using the model developed for prediction based on density of the samples. Thus, utilization of WPA as described herein could help to reduce the cost of procuring cement and in turn, enhance low-cost building construction. Also, with the developed model (showing dependence of water absorption coefficient on density), durability of sandcrete blocks exposed to moisture –prone environment could be easily predicted.

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Field evaluation of centre pivot sprinkler irrigation system in the North-East of Iran

Abedinpour M.

Journal of Water and Land Development

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2017

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no. 34

3--9

EN

A field evaluation of the technical performance of centre pivot sprinkler irrigation system was carried out during the maize crop growing season and when operating with different working speeds: S1 – 40%, S2 – 60% and S3 – 80%. For this goal, four uniformity measurements are to be considered in the evaluation; coefficient of uniformity (CU), distribution uniformity (DU), potential efficiency of low quarter application (PELQ) and actual efficiency of low quarter application (AELQ). The first step of evaluation of the sprinkler irrigation system is to compare the measured uniformity values with the standard values, DU ≥ 75%, CU ≥ 85%, AELQ and PELQ ≥ 90%. Effect of variation of speed produced CU values of 80.3, 82.7 and 86% for S1, S,sub>2, and S3 speed, respectively. Furthermore, DU standard value was obtained at S3 speed of 82%. Moreover, AELQ and PELQ were below the acceptable standard level of 90% for all speeds. Non-uniform water application leads to over or under irrigation in various parts of the field which can result in wasted water and energy. Therefore, regular evaluation of the irrigation equipments is needed to efficiently and effectively manage irrigation.

PL

Polową ocenę sprawności technicznej systemu deszczowania przeprowadzono w sezonie wegetacyjnym kukurydzy, kiedy system pracował z różną prędkością roboczą: S1 – 40%, S2 – 60% i S3 – 80%. W ocenie uwzględniono cztery miary jednorodności: współczynnik jednorodności (CU), jednorodność dystrybucji (DU), potencjalną wydajność dolnej ćwiartki aplikacji (PELQ) i rzeczywistą wydajność dolnej ćwiartki aplikacji (AELQ). Pierwszym etapem oceny systemu zraszania było porównanie zmierzonych wartości jednorodności z wartościami standardowymi: DU ≥ 75%, CU ≥ 85%, AELQ i PELQ ≥ 90%. Wpływ różnych prędkości wyraził się różnymi wartościami CU, wynoszącymi odpowiednio 80,3, 82,7 i 86,0%, gdy prędkość była równa S1, S2, i S3. Ponadto standardową wartość DU uzyskano, gdy prędkość S3 wynosiła 82%. Wartości AELQ i PELQ były poniżej dopuszczalnego standardu 90% dla wszystkich prędkości. Nierównomierne rozprowadzanie wody prowadzi do nadmiernego bądź niedostatecznego nawodnienia w różnych częściach pola, co skutkuje zmarnowaniem wody i energii. Z tego powodu niezbędna jest regularna kontrola urządzeń irygacyjnych dla wydajnego i efektywnego zarządzania nawodnieniami.

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Ocena funkcjonowania systemu nawodnień kroplowych w warunkach nawadniania oczyszczonymi ściekami

Wagner A., Jeznach J., Ptach W.

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

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2003

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Vol. 12, No. 2

20--26

EN

The quality of irrigation water has an impact on operation of irrigation system and influence on system efficiency. The main objective of the experiments was to examined the performance of drip system under conditions of low quality recycled water irrigation from tobacco manufacture. The results of uniformity coefficients were higher then 90% and performance of the drip system can be evaluated as acceptable.