Luca Sorelli

Université Laval | ULAVAL · Department of Civil Engineering

Despite decades of extensive studies, the mechanism of concrete creep remains a subject of debate, mainly due to the complex nature of cement microstructure. This complexity is further amplified by the interplay between water and the cement microstructure. The present study aimed to better understand the creep mechanism through creep tests on micro...

Despite extensive research efforts, understanding the time-dependent behavior of concrete remains an enigma due to the complex nature of cement microstructure. In this study, the statistical nanoindentation was employed to investigate the influence of relative humidity (RH) on the relaxation behavior of calcium silicate hydrates (C-S-H) in a cement...

Curvature-based damage detection has been previously applied to identify damage in concrete structures, but little attention has been given to the capacity of this method to identify distributed damage in multiple damage zones. This study aims to apply for the first time an enhanced existing method based on modal curvature analysis combined with wa...

Timber-Concrete Composite floors made of Cross-Laminated Timber (CLT) and Ultra-High-Performance Concrete (UHPC) boast remarkable efficiency in lightweight and slenderness. While the rapid UHPC hardening facilitates swift construction, the optimal shoring time depends on the effect of the UHPC autogenous shrinkage on the floor deflection. This stud...

This study focuses on developing a numerical model for the multi-ionic transport process in ordinary concrete (OC) and ultra-high-performance fiber-reinforced concrete (UHPFRC) in its sound and microcracked states. The theoretical background of multi-ionic transport was reviewed from the literature, and extended governing equations considering the...

The use of locally available industrial by-products as supplementary cementitious materials and mineral fillers is vital for reducing the embodied carbon of modern concretes. Spent pot lining (SPL), a by-product of the aluminum industry, is massively produced worldwide. SPL treated with the low caustic leaching and liming process (LCLL-ash) is no m...

This work aims at investigating the effect of multiple microcracks in Ultra-High Performance Reinforced Concrete (UHPFRC) occurring in service conditions on the apparent chloride diffusion which is critical to guarantee the design lifetime. First, series of preliminary static bending tests were carried out on three UHPFRC beams to characterize thei...

Treating SPL by the low caustic leaching and liming process generates an inert nonhazardous residue called LCLL Ash and a fluorite byproduct Calcined LCLL Ash that is ground into a fine powder demonstrates pozzolanic behavior in cement. The effect of the calcination temperature and fluorite byproduct addition on the reactivity of LCLL Ash was studi...

Timber-concrete composite (TCC) structures allow designing efficient building floors in terms of lightness, slenderness, and acoustic insulation. The late development of ductile notch connectors has further advanced TCC structures. This work aims to further optimize the shape of ductile notch connections and to optimally design TCC floors with mini...

Ultra-high performance concrete (UHPC) is a promising means to foster sustainable and resilient civil infrastructures as it allows reducing concrete volume, while enhancing structural performance and durability. However, UHPC applications are often limited by its high cost and by the availability of raw materials. This study aims to engineer a nove...

Spent potlining (SPLSpent Pot Lining (SPL)) is a hazardous waste produced by aluminumAluminum smelters. It is classified as a hazardous waste due to its contamination with fluoridesFluoride and cyanidesCyanide and its reactivity with water, generating explosive gases. After being industrially and hydrometallurgically treated by the Low Caustic Leac...

Chloride induced corrosion has been an important issue for many reinforced concrete structures. Over the past decades, numerous transport models has been developed to simulate the process. Most existing transport models focused and are validated only on well-known traditional materials such as regular concrete and cement paste. New materials such a...

Treating spent pot lining by the Low Caustic Leaching and Liming (LCLL) process creates an inert non-hazardous residue called LCLL Ash. Ground as a fine powder and calcined, LCLL Ash showed a pozzolanic behavior in cement. The effect of the calcination temperatures on LCLL Ash reactivity was studied by compressive strength activity index, Frattini...

To better provide zonal isolation for the production of oil and gas, low-density oil well cement (LD-OWC) filling a deep oil well was developed to reduce the high hydrostatic pressure caused by the cement slurry. The key mechanical properties of LD-OWC and related cracking susceptibility, nevertheless, have not been fully understood. This work was...

Non-uniform fiber distribution can significantly reduce the extension of multiple-cracking and favoring crack localizations in Ultra-High Performance Fiber Reinforced Concretes (UHPFRC) members under tension with important implication on the sought durability. This work aims at fostering the coupling between a Non-Destructive Technique, namely Magn...

Monitoring the damage evolution of existing concrete structures is critical for efficiently planning infrastructure maintenance and for selecting the optimal time for repairing or strengthening. The approach for detecting and locating damage in concrete structures depends on the measured vibration response of the structure and the type of sensors u...

Ultra-high performance concrete (UHPC) is a class of cement-based composites with enormous potentials for sustainable construction thanks to its outstanding compressive strength and cracking resistance. While the former allows saving material volumes and reducing the structural weight, the latter confers unprecedent durability. However, one of the...

In this paper, the sorption behavior of Ultra High-Performance Fiber Reinforced Concrete (UHPFRC) is experimentally investigated. As UHPFRC has a very low permeability, the sorption measurement presents an interesting challenge and has required the modification and optimization of the Dynamic Vapor Sorption Method (DVS) already applied for ordinary...

In this study, the importance of capillary suction was emphasized through its implementation in a hygrothermal transport model used to predict water transport in ordinary concrete. In the model, heat transfer is described by the classical Fourier equation. In addition, the homogeneous vapor diffusion is modeled using a gradient-driven Fick's law, a...

We demonstrate that azobenzene dye molecules, such as Methyl Orange (MO) and Acid Yellow 9 (AY9), can be used to control the motility of flagellar bacteria E. coli. The behaviour of bacteria is studied when dye molecules are photoexcited between trans and cis states. We show that the speed of bacteria can be changed by light up to +23 % and -45 %,...

Conventional de-icing methods with salts and snow removal causes considerable maintenance cost and outstanding indirect costs due to corrosion of the steel reinforcement of concrete infrastructures. Alternatively, heating systems based on Electrically Conductive Concrete (ECC) have been lately developed to reduce operational and reparation cost. Th...

Cross-Laminated Timber (CLT) structures have been emerging worldwide for residential floors in multi-storey buildings thanks to their lightness, fast construction and low ecological footprint. This work aims at fostering this application, which is often limited by vibrational and deflection limits, by investigating composite slab floors made of CLT...

A recent survey has showed that predicting the long-term deflection of existing concrete bridges after several decades is a great concern in civil engineering. The crux is to predict the creep deflection of a concrete structure after several decades from laboratory tests carried out over few months. This work aims at combining microindentation test...

A plastic insulation layer is used in timber-concrete composite (TCC) floors for preventing humidity exchange between timber and concrete However, the presence of this layer may affect the bond between the two materials and the ability to fill notch-type connectors with a negative effect on connection stiffness (K) and shear strength (VH). This iss...

Aluminum Spent Pot lining (SPL) is an industrial hazardous waste generated from aluminum electrolysis cells. The SPL separates in two parts, the first cut is rich in carbonaceous materials and the second cut is rich in vitrified refractory. Treating second cut SPL by the Low Caustic Leaching and Liming (LCL&L) process generates an inert non-hazardo...

The costs to maintain Québec’s infrastructure—most of which was built in the 1960s and 1970s—are considerable, and major maintenance and reconstruction will be required in the coming years. In recent years, aluminum associations promote the increase of aluminum use in infrastructure and especially in bridge construction. This research aims to inves...

Spent pot lining (SPL) is an industrial waste generated from aluminum electrolysis cells. LCLL-ash is the inert by-product coming from the treatment of the SPL refractory fraction at the SPL treatment plant (Jonquière, Canada). LCLL-ash has been ground to the fineness of the cement to substitute a part of cement in cement pastes. However, LCLL-ash...

Microindentation is today a powerful tool for rapidly characterizing the elastic modulus and the logarithmic basic creep of a cement paste. However, a theoretical work proved that a microindentation test with a sharp indenter shape involves stress concentration and delayed plasticity which can cause an overestimation of the estimated creep property...

Tobermorite is a natural mineral found in the microstructure of special concretes, such as autoclaved concrete and oil well cement, and along with jennite has been extensively studied for their analogy to the layered atomic structure of C–S–H. By employing creep microindentation tests, which allow measuring the logarithmic creep, this work aims at...

About 20 kt Spent Pot Lining (SPL) is generated by Rio Tinto in Québec each year from aluminum electrolysis cells and listed as industrial hazardous waste. After treatment by the Low Caustic Leaching and Liming (LCL&L) process, the refractory SPL becomes an inert non- hazardous material, called LCLL ash. The project discussed aims to valorize this...

Timber-Concrete Composite (TCC) structures allow taking synergistic advantage of the properties of both materials to optimize the overall performances in terms of lightness, slenderness, acoustic insulation, vibrational behaviour and environmental footprint. In the last years, ductile shear connectors have been developed to allow the structural duc...

The durability of concrete structures strongly depends on the water and chloride penetration in cracked concrete during its service life. This work aims at modeling the damage effect of tension stiffening behavior on the permeability for concrete tie specimen under tensile load by a dual lattice model, which considers hydromechanical couplings. Thr...

Owing to the micrometric size of the probed volume and the minute duration of a test, microindentation provides a unique tool to characterize the non-aging creep properties of a cement paste in hygral equilibrium. Microindentation techniques have been emerging as rapid technique to characterize the logarithmic creep rate of cement pastes. The objec...

While several works have investigated the effect of temperature on concrete creep, the effect of thermal activation on the multiple creep mechanisms is not fully understood. This work aims at investigating the thermal effect on the creep rate of cement pastes with different water-to-binder ratios (w/b) by microindentation technique. Firstly, severa...

Different kinds of ductile connectors have been lately developed for enhancing the structural ductility of Timber-Concrete Composite (TCC) structures. In particular, ductile notch connections can be designed by favoring the local compression failure of wood fibers. This work aims at further developing economic and ductile notch connector by conside...

The transport of chloride ions in concrete structures is not only due to diffusion but also to the advective effects of water movements and capillarity, mostly present with wet-dry cycles. These last two phenomena are currently very poorly modelled. A new system based on optical fibres was previously developed to measure the free chloride concentra...

Electrically Conductive Cementitious Composites (EC3) have been developed in the last decades to solve the drawbacks of conventional de-icing solutions, especially for urban regions with heavy snowfall where the cost of snow removal and accidents have been considerably increasing. This work aims at developing Electrically Conductive Concrete (ECC)...

Ultrahigh-performance fiber-reinforced concrete (UHPFRC) is endowed with outstanding durability. The first results of accelerated migration tests with an adapted procedure highlighted a very low chloride permeability profiles for undamaged UHPFRC with organic and metallic fibers. However, some of the samples with steel fibers showed useless results...

Timber-concrete composite (TCC) structures provide a breakthrough solution for multi-storey buildings. Besides the importance of the connection stiffness, recent research has focused on ductile connectors. This work aims at developing an economic new cast-in-place connector to guarantee the suitable stiffness and structural ductility. A new composi...

The development of Ultra-High Performance Concrete (UHPC) opened new research directions for enhancing the architectural design, sustainability and serviceability of concrete structures. However, the costs and resource intensiveness trigger the need for innovative UHPC mix design incorporating alternative materials, such as post-consumption Glass P...

The ever-increasing need to maintain aging existing reinforced concrete structures, especially in severe winter environments, in good condition and a cost-effective manner arises mainly in structural health monitoring methods, where it is necessary to adopt approaches that allow early detection of corrosion. Chloride-induced corrosion is a signific...

The study of the early-age behavior of Timber-Concrete Composite (TCC) structures is of great interest as it provides valuable information for manufacturing specification development, quality control, and optimization of the formwork design. In this study, the results of the continuous monitoring of the short-term behavior of TCC slabs using Brillo...

Timber-Concrete Composite (TCC) structures are emerging worldwide in several civil engineering applications as an effective construction system in terms of structural stiffness and strength, lightness and vibrational behavior. This work aims at fostering an innovative TCC solution for residential floors that combines a thin slab of Ultra-High Perfo...

Sustainability decision making is a complex task for policy makers, considering the possible unseen consequences it may entail. With a broader scope covering environmental, economic, and social aspects, Life Cycle Sustainability Assessment (LCSA) is a promising holistic method to deal with that complexity. However, to date, this method is limited t...

Nanomaterials are currently attracting a rising research attention in versatile realms including the concrete industry. Thus, the promising properties of nanocellulose materials (NCM) are expected to unveil new horizons for enhancing concrete performance. This paper discusses the perspectives of using NCM for tailoring the properties of cement comp...

Accelerated migration tests which are commonly used to measure chloride diffusion in ordinary cement-based materials cannot be directly applied to composite with very low permeability, such as Ultra High-Performance Fiber Reinforced concretes (UHPFRC). In order to assess the UHPFRC enhancement on the structural durability, there is a critical need...

This work aims to present a complete full coupling eXtended finite element formulation of the thermo-mechanical problem of cracked bodies. The basic concept of the extended finite element method is discussed in the context of mechanical and thermal discontinuities. Benchmarks are presented to validate at the same time the implementation of stress i...

Plastic waste is today an crucial environmental issue for which innovative recycling techniques are needed. This research aims at investigating the feasibility of replacing fine aggregate in concrete by recycled plastics from real post-consumer streams. Different kind of plastics were sorted in Material Recovery Facilities (MRF) to realize differen...

Ultra-High Performance Fiber Reinforced Concrete, unlike conventional concrete, shows a remarkable tensile strength which is paramount for guaranteeing the crack resistance and durability. However, tensile tests on UHPFRC are not widely employed due to the difficulty to guarantee uniform tensile stress during the entire loading. To overcome this di...

Current demand for novel highly sustainable concrete urges improving the links between chemical and mechanical effects of supplementary cementitious materials (SCMs) on the microstructure of blended-cement pastes. In this work, coupled NanoIndentation and Quantitative Energy Dispersion Spectroscopy (NI-QEDS) was applied to disclose chemo-mechanical...

Recent studies have showed that microindentation techniques allow assessing the logarithmic creep rate of a cement paste in good correlation with the long-term creep rates measured by compressive tests at macroscopic scale. After having applied microindentation techniques to characterize the effect of relative humidity (RH) on both the creep and re...

A better understanding of the microstructural features of cement matrices incorporating supplementary cementitious materials (SCMs) represents key knowledge for engineering more sustainable concrete infrastructures. By fostering the coupling of nanoindentation techniques with quantitative energy-dispersive X-ray spectroscopy (NI-QEDS), this work ai...

Alkali-silica reaction (ASR) is a major issue for the durability of concrete structures worldwide. Fostering recent microindentation works on the elastic property of ASR products, this work aims at further characterizing their viscous property. In particular, this study focuses on the relaxation behaviour of ASR crystalline products which are prefe...

Engineering cement-based composites requires a comprehensive understanding of the microstructure features governing macroscopic properties. This work aims to foster the latest chemo-mechanical technique to disclose the micro-mechanical properties of intimately intermixed phases. Considering a typical Portland cement paste as a study case, we compar...

This study investigated mechanical properties of biocomposites developed from recycled polylactic acid (PLA) from packaging industry and treated cellulosic fibers from pulp and paper solid waste. Microwave and enzymatic treatments were used for extraction and surface modification of hydrophilic cellulosic fibers. Enzymatic treatment was specificall...

Structural design with highly flowable Fibre Reinforced Concrete has to duly take into account the preferential alignment of fibers, which can be governed through the rheological properties of the fluid mixture and the casting process and by the geometry of the structure. The possibility of predicting the fiber alignment, by tailoring the casting p...

Crack propagation in carbon cathode used in the aluminium industry has been investigated through flexural tests on notched specimens. The main parameters of interest were the geometrical evolution of the crack and the stress intensity factor at the tip ends. The latter, in the case of interfacial fracture in two-dimensional geometries, can be relat...

A recent survey has revealed that the deflection of concrete bridges increases incessantly over a period of more than 20years and can exceed by far the predictions of current design recommendations. This work applies microindentation techniques, which allow quickly assessing the long term rate, to investigate the effect of relative humidities on bo...

Timber-concrete composite (TCC) structures have been emerging in several industrial applications due to potential to simultaneously optimize their structural stiffness, dynamic vibration and ecological imprint. However, when one considers nonlinear behaviour of timber-to-concrete connections and the cracking of the concrete slab, the structural ana...

Ultra High Performance Fiber Reinforced Concrete (UHPFRC) structures are emerging in several engineering applications as their outstanding tensile strength and ductility allow engineers to develop new structural concepts and overcome construction limits. Optimization of the UHPFRC fiber ratio, which has significant economic and technical relevance,...

Results of the evaluation of a new bioproduct produced through fermentation of a mixed culture of microorganisms as a plasticizer in concrete are presented. The product, generically known as the Efficient Microorganism (EM) has proven potential for use as chemical admixture in concrete. The product, in a diluted version, shows a moderate plasticizi...

Delayed deformations in concrete under sustained loading may depend on complex chemo-hydro-mechanical phenomena. Generally, the creep deformation of a cement paste is distinguished in the short-term and long-term. Simply speaking, the former can be associated to the diffusion of gel water in pores and cracks and it is mainly volumetric (i.e., volum...

The mechanical properties of azobenzene-containing polymer films are statistically measured by instrumented nanoindentation experiment in the dark and under illumination in the absorption band of the azobenzene molecules, with special emphasis on the creep behavior and recoverability. We use Dispersed Red 1 azobenzene derivatives, which remain in t...

The mechanical properties of concrete produced with effective microorganisms (EM)-based bioplasticizer are investigated by means of statistical nanoindentation, and compared to the nanomechanical properties of concrete produced with ordinary superplasticizer (SP). The resort to nanoindentation enables to survey the elasticity, hardness and long-ter...

Les structures en BFUP font leur apparition dans de nombreuses applications d'ingénierie grâce à l’excellente résistance en traction de ces matériaux, qui permet aux ingénieurs de développer de nouveaux concepts de structure et de dépasser les limites de construction actuelles. Ce document met l'accent sur l'analyse structurelle d'une nouvelle pass...

This work aims to characterize the creep behavior of the major microstructure constituents of cement paste by means of a novel approach which combines Nanoindentation Technique (NT) and Scanning Electron Microscopy with X-ray microanalysis (SEM-EDS). We first performed a large grid of nano-indentation tests on different cement paste samples. The te...

The durability of concrete materials with regard to early-age volume changes and cracking phenomena depends on the evolution of the poroelastic properties of cement paste. The ability of engineers to control the uncertainty of the percolation threshold and the evolution of the elastic modulus, the Biot–Willis parameter and the skeleton Biot modulus...

Since 2002, ultra high performance fiber-reinforced concretes (UHPFRC) have been increasingly applied. They have also been the focus of extended research efforts worldwide. The results of these works have served as the background for updating the Association Française de Génie Civil(AFGC) recommendations, in addition to rewriting of the part devote...