Experimental Investigation on Carbonation Behavior in Lime‐Stabilized Expansive Soil

Abstract

e carbonation behavior of lime-stabilized expansive soil is important for assessing the stabilization efficiency from the perspective of durability. In this study, the accelerated carbonation tests, measurement of pH value distribution, and the free swell ratio tests were conducted to investigate the evolutions of carbonation depth, carbonation extent, and expansive potential of limestabilized expansive soil. XRD, MIP, and SEM techniques were adopted as supplements to reveal the carbonation mechanism. Results demonstrated that the carbonation depth of lime-stabilized expansive soil increased significantly as time elapsed; however, the rate of increase reduced when the carbonation time increased. Higher carbonation depth was obtained at higher temperature and CO 2 concentration and lower relative humidity, which was described by an empirical model. Fully, partly, and noncarbonated zones were subsequently presented with an increase in the depth of the soil. e expansive potential of lime-stabilized expansive soil was partially recovered during carbonation. e obtained linear relationships between the free swell ratio and pH value were adopted to describe the evolution of expansive behavior with carbonation time and depth. In microstructural analysis, the conversion of portlandite into calcium carbonate was significant, which resulted in changes in microstructure and controlled the carbonation behavior.

Experimental Study on the Cracking and Mechanical Properties of Lime Soil with Different Slaking Conditions of Newly Repaired Earthen City Walls

“…The lime soil continues to slake, and Ca(OH) 2 reacts with CO 2 in the air to form CaCO 3 . The reaction formula is as shown in (2). This reaction will consume part of the OH− generated by the reaction of CaO with water.…”

“…Lime and soil are mixed to form lime soil, which has the characteristics of high strength, good integrity, economic material and convenient construction [1,2]. As a repair material, lime is widely used to improve the mechanical properties of rammed soils in the restoration of ancient rammed earth projects [3][4][5][6][7][8][9][10][11].…”

Isolated Effect and Sensitivity of Agricultural and Industrial Waste Ca‐Based Stabilizer Materials (CSMs) in Evaluating Swell Shrink Nature of Palygorskite‐Rich Clays

“…Expansive soils are located in various regions of Asia including China, India, Iran, Oman, Pakistan, and Saudi Arabia [29,[70][71][72][73][74][75][76]. e percentage land covered in countries where expansive soils are found in abundance has been illustrated in Figure 2.…”

Importance‐Performance Analysis of Prefabricated Building Sustainability: A Case Study of Guangzhou

“…Prefabricated buildings, which are an important part of construction industrialization, are receiving an increasing attention [32,33]. Previous research has used various terms related to prefabricated buildings, including "prefabricated" [34], "prefabricated concrete building" [35], "industrialized building" [36,37], and "off-site building" [38].…”