A Comparative Evaluation of Cement and By-Product Petrit T in Soil Stabilization

Abstract

This study presents a comparison between the effectiveness of adding low binder amounts of industrial by-product Petrit T as well as cement to modify and improve fine-grained soil. Binder amount was added by soil dry weight; cement at 1%, 2%, 4% and 7% and Petrit T at 2%, 4% and 7%. The unconfined compressive strength (UCS) was used as an indicator of soil strength. In addition, the consistency limits, laser particle size analysis, and pH tests were also conducted on the treated soil. The samples were cured at 20 • C for different periods from 7 to 90 days before testing. Results indicate that cement is more effective at improving the physical and engineering properties of the treated soil. Soil plasticity index decreases after treatment and with time. Liquidity index and the water content to plastic limit ratio are introduced as new indices to define the improvement in the workability of treated soil. Soil particle size distribution is changed by reducing the clay size fraction and increasing the silt size fraction after treatment. The findings confirm that adding small binder contents improve soil properties, which subsequently reduce the environmental threats and costs that are associated with using a high amount of binder. Enhanced soil strengths, reduced soil plasticity and swelling potential are the most desirable outcomes from the treatment. For certain soil stabilization applications, the cost of the binder itself could result in a considerable saving in the overall costs of the project [24]. Petrit T is a waste product from sponge iron production [18]. It is considered a cheap by-product material [25]. Therefore, in order to decrease the environmental impact and costs, finding new binders as alternatives to Portland cement is important. Thus, there is a need to compare the effectiveness of using cement and by-product Petrit T as stabilizing agents.This paper presents a comparative evaluation between using Portland cement and by product Petrit T to enhance the physical and mechanical properties of sandy clayey silt soil. An extensive experimental program was carried out in this study, including tests of unconfined compressive strength, laser particle size, consistency limits, and pH tests, using various binder amounts and curing periods. Materials and MethodsThe samples used in this study were prepared from a natural soil from Gothenburg, south west coast of Sweden. The soil consists of 55% silt, 29% fine sand and 16% clay. The natural water content is 30%, the liquid limit 37% and the plastic limit 20%. The optimal moisture content is 12%, and the proctor density is 1.97 t/m 3 . The ignition test showed that the soil has 4% organic content. Therefore, according to the Swedish standard, natural soil is classified as sandy clayey silt (saclSi) with low organic content [26][27][28].Natural soil was firstly homogenized and then mixed with Petrit T as well as the cement in various percentage from 1 to 7% as dry mass of soil and cured for 7, 14, 28, 60 and 90 days before testing.Unconfined compressive tests (U...

Strength and Durability of Cement-Treated Lateritic Soil

“…Conversely, the strain decreased from 2.58% for untreated to 2.08%, 1.56%, 1.37%, and 1.19% for 3%, 6%, 9%, and 12% cement content within 7 days curing. The results obtained for the ductility change with increasing cement and curing time in this research were compatible with [2,70,82,100] in that the authors indicated higher brittleness for high cement content and more curing time. Similarly, in the current study, the ductility changes of a specimen mixed with 3% cement, with a curing time, were not considerable, whereas the ductility significantly decreased for 6%, 9%, and 12% cement.…”

“…demonstrate that compressive strength was enhanced with cement content and curing time, the effectiveness of 3% cement was not significant. This behavior could be attributed to the low pH value, whereby the cement could not improve soil strength effectively at a pH value smaller than 12.4 [82]. The UCS results in Figure 7 show that the 6% cement was adequate for stabilizing the lateritic soil to achieve a minimum UCS of 0.8 MPa, according to Malaysia Public Works Department (MPWD) standards.…”

“…demonstrate that compressive strength was enhanced with cement content and curing time, the effectiveness of 3% cement was not significant. This behavior could be attributed to the low pH value, whereby the cement could not improve soil strength effectively at a pH value smaller than 12.4 [82].…”

“…In regard to Table 4, the obtained equation for E50 in this study was within the range of previous studies, particularly the study carried out by Rashid et al [2] in Malaysia. [82] Cement-admixed (5-20%) Bangkok clay in Thailand E 50 = 150 q u [102] Cement-stabilized (10%) and cement kiln dust-stabilized (10-13%) high-plasticity soft Bangkok clay in Thailand E 50 = 113 q u [103] Cement-stabilized (10-20%) marine clay in China E 50 = (150-275) q u [104] Cement-treated (3-9%) laterite soil in Cameroon E = 117.39 q u − 36.812 [86] 3.5. Durability…”

“…In this regard, one can refer to [43] for more detail. Therefore, OPC could still be considered an effective stabilizer agent in the construction of transportation infrastructure, as Al-Jabban et al [81] stated, based on their research that cement was more effective in improving the engineering properties of fine-grained soil compared to Petrit-T, a by-product obtained from sponge iron manufacturing [82]. Although some studies have been conducted in determining the optimum OPC for low-volume roads according to MPWD standards, the small number of studies and discrepancies between obtained results motivated the conducting of this research.…”