The influence of lime powder on the behaviour of clay soil

Visoka cijena zemljišta i značenje graditeljstva u modernom svijetu uvjetovali su potrebu za ojačanjem glinovitog tla slabe nosivosti. Stabilizacija takvog tla provodi se dodavanjem raznih aditiva. Zbog svoje niske cijene, dostupnosti i pozitivnog utjecaja na čvrstoću, vapno se tradicionalno koristi za stabilizaciju slabo nosivih i osjetljivih vrsta tla. U ovom se radu vapnena prašina u udjelu od 0, 2, 4, 8 i 16 % od težine suhog tla miješa s kaolinitnim glinovitim tlom te se istražuju razni inženjerski parametri u razdoblju njege tijekom 90 dana. U tom razdoblju njege, za razne postotke vapnene prašine istražuje se promjena pH-vrijednosti, Atterbergove granice, optimalan udio vode i maksimalna suha jedinična težina modificirane gline. U okviru određivanja optimalnog udjela vapnene prašine, provode sei ispitivanja jednoosne tlačne čvrstoće (UCS) te kalifornijskog indeksa nosivosti (CBR). Youngov modul određuje se na temelju pokusa UCS i definicije krivulje naprezanja i deformacija. Rezultati pokazuju znatan porast efektivne učinkovitosti vapna dodanog u tlo te znatan porast maksimalne tlačne čvrstoće (qu), kohezije i Youngovog modula.High price of land and importance of modern construction has imposed the need to strengthen weak clay soils. The stabilization of these soils has been conducted using various additives. Due to its low cost, availability, and positive impact on resistance, lime has traditionally been applied for stabilisation of poor and sensitive types of soils. In this research, lime powder, added in the percentages of 0, 2, 4, 8 and 16 of the dry soil weight, was mixed with kaolinite clay soil and its various engineering parameters were investigated during the curing time of 90 days. PH change, Atterberg Limits, optimum water content, and the modified clay maximum dry unit weight, were determined at different percentages of lime during the curing time. In the scope of determination of an optimum lime powder content, the Unconfined Compressive Strength tests (UCS) and CBR tests were conducted. The Young’s modulus was determined based on UCS testing and definition of stress-strain curve. The results showed a significant increase in the effective, responsive performance of lime in the soil and a remarkable increase in the maximum compressive strength (qu), cohesion, and Young’s modulus

AN ASSESSMENT ON STABILIZATION OF EOLIAN FINE-GRAINED SOILS USING WIND TUNNEL

ABSTRACT: Control of soils wind erosion particularly in arid and semi-arid regions has been seriously paid into attention due to several causes including to prevent the destruction natural resources, reducing air pollution, reducing aerosol transmission and the problems it causes in transportation. Measurement of factors affecting on wind erosion in field conditions is difficult and uncontrollable. Hence, use of wind tunnel device is addressed as one of feasible methods. In fixed wind tunnels, in order to measure soil erosion, trays containing soil shall be placed in the tunnel floor and the wind blows with a given specification. Tray weight difference between the two times of weighing indicates erosion rate of a given level. In present research, wind tunnel was manufactured and launched in laboratory. Wind speed in the tunnel is in 0-40 km/h range. Experimental results showed that the rate of soil erosion and loss is reduced with increased other soil particles versus wind erosion. General and localized erosion phenomena on soil surface were investigated according to soil particles size and uniformity of the samples coating surface