Effect of Wood Extractives of Some Sudanese Wood Tree Species on Portland cement Setting

الموضوعات

زراعة

الملخص

The experiments of this study were conducted in the National Center for Research and Buildings and Roads Research Institute, Khartoum State.The objectives of this study are to detennine the extractives content of some Sudanese species and investigate the effect of extractives of four potential species on retarding cement setting using different extraction methods and extractives percentages.Thirteen Sudanese species were collected from different sites in Sudan to study the extractives content. Then four potential species (Acacia nilotica, Calotropis procera, Cupressus lucitanica and Eucalyptus microtheca) . were selected to study the effect of species, extraction method (cold water, hot water and 1 % NaOH) and extractives percent (0.5, 0.6 and 0.7%) on cement strength. After adding the extracts to cement, mortar cubes were prepared for testing the compressive strength after soaking in water for 28 days, using a Universal Testing Machine. Qualitative analysis was done to the extractives of the studied species.The results showed that the extractives content of the thirteen studied species varied between 5.9% and 11.2% when extracted with cold water, between 19.5% and 25.6% when extracted with hot water and between 23% and 39.6% when extracted with 1 % NaOH.The compressive strength of the extractives-cement mixtures of the four species varied between 450.8 Kg/cm2 and 1024.6 Kg/cm2. The influence of each of the studied factors (species, extraction method and extractives percent) varied with the levels of the other factors.When using cold water extractives, the most inhibitory species was C. procera. When using hot water extractives, the most inhibitory species were A. nilotica, E. microtheca and C. lucitanica. When using 1 % NaOH extractives, the most inhibitory species was C. procera.The effect of extraction method on compressive strength depends on the species and extractives percent. For example, when using A. nilotica extract, the addition of 7% cold water extractives had the highest inhibitory effect on cement setting. When using C. procera extract, differences between the extraction methods were significant at all extractives the addition of 0.5 and 0.6% cold water extractives were inhibitory on cement compressive strength.Significant difference between extraction methods for C. lusitanica, were found only when adding the extractives at 0.6%. The extractives of hot water and 1% NaOH were more inhibitory than those of cold water.When using E. microtheca extract, there were no differences between the extraction methods extractives on cement regardless of the amount of extractives added.. The results of the qualitative analysis (presence of sugars, tannin, fats, alkaloids and flavanoids) and the determination of the pH were not helpful in explaining the variations in the effect of species on cement strength.

روابط وملفات

التعريف والنوع

رقم الوثيقة

0a0d3d3c-f03c-4003-ba43-cd17d72985e6

رقم العقد

0

نوع الوسائط

Crawler

نوع المحتوى

الرسائل العلمية

صيغة المصدر

رسائل ماجيستير

نوع الملف

pdf text

أسماء الملفات

1623322_1.pdf

بيانات النشر

ألقاب المؤلفين

[{"name_ar":"Balmina Krustof-Abd El Azim Yassin","title_ar":"اشراف","title_en":"Supervision"},{"name_ar":"احمد محجوب","title_ar":"اعداد","title_en":"Preparation"}]

اللغة

English

المصدر والدورية

اسم المصدر

Effect of Wood Extractives of Some Sudanese Wood Tree Species on Portland cement Setting

المحتوى والصفحات

عدد الصفحات

0

إشراف وإعداد

الإشراف

Balmina Krustof-Abd El Azim Yassin

الإعداد

احمد محجوب

الاقتباسات الببليوغرافية