Concrete Silos: Failures, Design Issues and Repair/Strengthening Methods

Abstract

The review article investigated failure, design issues, repair and strengthening of reinforced concrete (RC) silos, primarily in agricultural set-ups. The durability of RC structures was influenced by the nature of the bulk solids, materials used in the reinforcement of the structures. Traditionally, high-grade steel has been used in silo wall reinforcement because it is affordable and readily available. However, it is susceptible to corrosion. In contrast, fiber-reinforced polymers (FRP) have better mechanical properties (tensile strength, elastic modulus, and Poisson’s ratio) and are not corroded. Additionally, there are limited scalable and facile methods for commercial production. The low ductility elevates the risk of brittle fracture in external pre-stressing concrete repair/strengthening. Beyond the material factors, the existing silo design codes such as BS EN 1991-4:2006, Australian Standard AS 3774-1996, and American Society of Agricultural Engineers ANSI/ASAE EP433 DEC1988 (R2011), and American Concrete Institute ACI 313-97 are limited by simplified characterization of loading/unloading scenarios and exclusion of specific hopper geometries and configurations. The funnel and mass flow scenarios and accumulation of bulk materials contribute to silo failure. In brief, the present repair/strengthening strategies (external pre-stressing, insertion/removal of inserts, shear columns, and FRPs alternatives to steel) do not adequately address the diverse variables that elevate the risk of material failure.

Analyzing the Structural Integrity and Efficiency of Silos: A Comparative Study of Plate Thickness Variations

“…Evaluation of stresses, strains, deformations, buckling behavior, and failure modes are important components in silo structural analysis (Maraveas, 2020), (Alfanda et al, 2022). To model and examine the structural reaction of silos, engineers use sophisticated computer methods including computational uid dynamics (CFD) and nite element analysis (FEA).…”

Seismic Analysis of Reinforced Concrete Silos under Far-Field and Near-Fault Earthquakes

“…Nevertheless, the silo wall rigidity is inspected for silos subjected to ground motions [14] and the response of the ensiled material under earthquakes [15]. Furthermore, a study was implemented to discuss the causes of the major failures in singular silos [16] and a group of silos under seismic excitation [17].…”

Sensors for Structural Health Monitoring of Agricultural Structures

“…The real-time monitoring of the flow profile is vital because the uneven distribution of solid materials might result in the unequal distribution of the grain moisture content, axial and hoop forces, pressure ratio, and internal friction angle [ 6 ]. The relationship between solid bulk flows and different types of silo obstructions, including noise and vibration, segregation, ratholing, and arching, which result in the buildup of overpressures on the hopper walls, reinforce this argument.…”

“…The scope of the review focuses on sensors for measuring chloride ingress [ 2 ], corrosion activity, carbonation, concrete (electrical) resistivity, permittivity, and stress/strain [ 3 ] and the following thematic areas: sensors for monitoring and health diagnosis of agricultural structures, sensors for concrete, steel, timber [ 4 ], electrochemical, fiber optic, wireless, ultrasonic, fiber Bragg grating sensors, self-sensing materials, the utility of sensors in facilitating the repair process, mitigation of failure, initiation of appropriate action, improving the durability and useful life, and the replacement of agricultural structures. The measurement of corrosion activity is critical in steel farm structures, given the higher susceptibility to redox reactions and gradual environmental degradation [ 5 , 6 ].…”

“…Failure analyses of structural damage of silo structures have established that corrosion of steel reinforcement, water, chemical attack, absence of horizontal and vertical reinforcements [ 13 ], and non-compliance or failure of the building design codes leads to structural damage. The commonly applied building codes for silos include AS 3774-1996, ANSI/ASAE EP433 DEC1988, ACI 313-97, and BS EN 1991-4:2006 [ 6 ]. Secondary causes of failure include wall damage, connection failures, and the lack of adequate beam support [ 14 ].…”