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The paper seeks to bridge the already familiar benefits of 3D printing (3DP) to the rehabilitation of cultural heritage, still based on the use of complex and expensive handcrafted techniques and scarce materials.

A compilation of different information on frequent anomalies in cultural heritage buildings and commonly used materials is conducted; subsequently, some innovative techniques used in the construction sector (3DP and 3D scanning) are addressed, as well as some case studies related to the rehabilitation of cultural heritage building elements, leading to a reflection on the opportunities and challenges of this application within these types of buildings.

The compilation of information summarised in the paper provided a clear reflection on the great potential of 3DP for cultural heritage rehabilitation, requiring the development of new mixtures (lime mortars, for example) compatible with the existing surface and, eventually, incorporating some residues that may improve interesting properties; the design of different extruders, compatible with the new mixtures developed and the articulation of 3D printers with the available mapping tools (photogrammetry and laser scanning) to reproduce the component as accurately as possible.

This paper sets the path for a new application of 3DP in construction, namely in the field of cultural heritage rehabilitation, by identifying some key opportunities, challenges and for designing the process flow associated with the different technologies involved.

Reinforced concrete is a very durable material, often specified because of the expectations of a long maintenance‐free life. However, it is also an easily abused material. It derives its strength from chemical change and both its physical and its chemical form provide corrosion protection to the reinforcement. It is, therefore, highly sensitive to the contents of the mix and in particular to any additives or pollutants which might affect the chemical composition.

The purpose of this paper is to focus on compressive strength modelling of cementitious mixtures like mortar and Roller-compacted concrete (RCC) containing rubber aggregates from shredded worn tires and filler using adaptive neuro fuzzy inference systems (ANFIS).

The volume substitution contains a ratio of rubber aggregates vs sand in mortar and with crushed sand in RCC and ranges from 0 to 50 per cent. As for the filler, they are substituted with sand by 5 per cent in mortar mixture. The methodology consists of optimizing the percentage of substitution in cementitious mixtures to ensure better mechanical properties of materials like compressive strength. The prediction of compressive strength and the optimization of cementitious mixtures encourage their uses in such construction pavements, in area games or in other special constructions. These cementitious materials are considered as friendly to the environment by focussing on their improved deformability.

The results of this paper show that the performance of the constructed fuzzy method was measured by correlation of experimental and model results of mortar and RCC mixtures containing both rubber aggregates and filler. The comparison between elaborated models through the error and the accuracy calculations confirms the reliability of the ANFIS method.

The purpose of this paper is to assess the performance of the constructed fuzzy model by the ANFIS method for two types of cementitious materials like mortar and RCC containing rubber aggregates and filler. The fuzzy method could predict the compressive strength based on the limited measurement values in the mechanical experiment. Furthermore, the comparison between the elaborated models confirms the reliability of the ANFIS method through the error and the accuracy calculations for the best cementitious material mixtures.

A study on the mechanical characteristics of cementitious mortar reinforced with basalt fibres at ambient and elevated temperatures was carried out. To investigate their effect, chopped basalt fibres with varying percentages were added to the cement mortar.

All the specimens were heated using a muffle furnace. Flexural strength and Compressive strength tests were performed, while monitoring the moisture loss to evaluate the performance of basalt fibre reinforced cementitious mortars at elevated temperatures.

From the study, it is clear that basalt fibres can be used to reinforce mortar as the fibres remain unaffected up to 500 °C. Minimal increases in flexural strengths and compressive strengths were measured with the addition of basalt fibres at both ambient and elevated temperatures. SEM pictures revealed fibre matrix interaction/degradation at different temperatures.

The current study shows the potential of basalt fibre addition in mortar as a reinforcement mechanism at elevated temperatures and provides experimental quantifiable mechanical performances of different fibre percentage addition.

Self-healing concrete is a revolutionary building material that will generally reduce the maintenance cost of concrete constructions. Self-healing of cracks in concrete structure would contribute to a longer service life of the concrete and would make the material more durable and more sustainable. The cementitious mortar with/without incorporating encapsulates at different percentages of slag replacement with the cement mix improves autogenous healing at different ages. Therefore, this study’s aim is to develop a self-healing cementitious matrix for repair and retrofitting of concrete structures.

In the present work, waste straw pipes are used as a capsule, filled with the solution of sodium hydroxide (NaOH), sodium silicate (Na₂SiO₃) and colloidal nano-silica as self-healing activators. An artificial micro-crack on the control and blended mortar specimens at different percentages of slag replacement with cement (with/without encapsulation) is developed by applying a compressive load of 50% of its ultimate load-carrying capacity. The mechanical strength and ultrasonic pulse velocity, water absorption and chloride ion penetration test are conducted on the concrete specimen before and after the healing period. Finally, the self-healing activity of mortar mixes with/without encapsulation is analysed at different ages.

The encapsulated mortar mix with 10% of slag content has better self-healing potential than all other mixes considering mechanical strength and durability. The enhancement of the self-healing potential of such mortar mix is mainly due to hydration of anhydrous slag on the crack surface and transformation of amorphous slag to the crystalline phase in presence of encapsulated fluid.

The self-healing activities of the slag-based cementitious composite are studied for a healing period of 90 days only. The strength and durability performance of the cracked specimen may be increased after a long healing period.

The outcome of the work will help repair the cracks in the concrete structure and enhances the service life.

This study identifies the addition encapsulates with a self-healing activator fluid that can recover its strength after minor damage.

The purpose of this paper is to analyse two parameters relevant to the physical‐mechanical performance of external renders, mainly, bulk density and apparent or open porosity, by performing laboratory tests on samples collected under real in‐service conditions.

The test procedure (sample preparation and techniques used) and its relationship with the overall performance characteristics and with any anomalies are discussed for each parameter. The analysis of the results covers seven case studies and 15 walls with renders made on site (cementitious and cement‐lime based) and non‐traditional or pre‐mixed renders.

It was concluded that reliable relationships could be established between the test results and other physical parameters relevant to the mechanical and water‐related behaviour of different types of cementitious renders. Notwithstanding the usual drawbacks of laboratory tests (more time‐consuming, higher costs and greater destruction of the walls), the use of small samples and the additional data obtained in terms of in‐service performance justify the use of this type of test.

The originality of this approach comes from the advantage of conducting both laboratory tests (reliability and standardization) and in situ tests (testing real materials subjected to in‐service conditions). Current practice is either to test virgin materials in quasi‐perfect laboratory conditions (therefore far from reality) or to test materials on site using standard in situ techniques sensitive to subjectivity and in far from ideal environmental conditions.

Introduction Concrete is a mixture of naturally occurring geological aggregates bonded together by a cementitious agent which ‘sets’ by reacting with water. This setting process is called ‘hydration’ and is not a dissolution process. The advantages of concrete are as follows:

This paper employs a textile reinforcement strain comparison to study the response of Textile Reinforced Mortars (TRM) strengthened reinforced concrete one-way slab members in flexure using the finite element method. Basalt TRM (BTRM) is a relatively new composite in structural strengthening applications. Experimental data on BTRMs are limited in the literature and numerical analyses can help further the understanding of this composite. With this notion, Abaqus finite element software is utilised to create a numerical method to capture the mechanical response of strengthened slab members instead of time-consuming laboratory experiments.

A numerical method is developed and validated using existing experimental data set on one-way slabs strengthened using Basalt TRMs from the literature. An explicit solver is utilised to analyse the finite element model created using calibrated Concrete Damage Plasticity (CDP) parameters according to the experimental requirements. The generated model is applied to extract load, deflection and rebar strains sustained by strengthened reinforced concrete slabs as observed from the experimental reference chosen. The applicability of the developed model was studied beyond parametric studies by comparing the generated finite element tensile strain by the textile fibre with available formulae.

CDP calibration done has shown its adaptability. The predicted results in the form of load versus deflection, tensile and compressive damage patterns from the numerical analysis showed good agreement with the experimental data. A parametric study on various concrete strength, textile spacing and TRM bond length obtained shows TRM’s advantages and its favourability for external strengthening applications. A set of five formulae considered to predict the experimental strain showed varied accuracy.

The developed numerical model considers strain sustained by the textile fibre to make results more robust and reliable. The obtained strain from the numerical study showed good agreement with the experiment results.

This study aims to investigate the size effect of the patched repairing material applied to the cracked beam.

Numerical analysis was conducted on a simply supported cracked beam with a dimension of 200 × 25 × 15 cm using ABAQUS software. The behavior of concrete and engineered cementitious composites (ECC) in the simulation are described as concrete damage plasticity model. Linear elastic-plastic model was used to represent the behavior of rebar steel. The type of patching consisted of the varying ratio of lengths and depths, including patching length to total length ratios of 0.2, 0.3 and 0.4, and patching depth to total depth ratios of 0.2, 0.3, 0.4 and 0.5.

Results show that variations in the patching length and depth ratios affect the maximum flexural load, stiffness and ductility of the repaired beam. It was also found that repairing the cracked beam by using ECC provides higher flexural load of the beam than the use of conventional concrete, owing to the superior tensile strength of ECC.

ECC is the cementitious-based mortar that contains the special selected poly vinyl alcohol fiber having high tensile strength. ECC has been known to exhibit high ductility, high tensile strength and improve durability performance. Thus, ECC is suitable as repairing material for patching cracked beam. By investigating the size of the patched repairing material applied to the cracked beam, the structural performance of repairing beam and the effectiveness of the various patching size were achieved.

This paper presents the outcomes of the international project “Protecting Landscape Heritage: a requalification project as an instrument for the re-birth of Quang Tri Old Citadel in Vietnam”, achieved with scientific cooperation between the Università Politecnica delle Marche (Italy) and Hue University of Sciences (Vietnam) funded by the Italian Ministry of Foreign Affairs and International Cooperation and Ministry of Science and Technology of Vietnam. The research focuses on the Quang Tri Citadel, founded in 1809 and now in an advanced state of degradation.

For the purpose of rehabilitation, the wide multidisciplinary project first examined the historical context of the military model, the architectural aspects of the structure, the characterization of the existing materials, the degradation levels of different parts, and, finally, a proposal of the suggested interventions.

The original structure and geometry were extrapolated and studied. Building materials were produced with nearby raw materials. Firing temperatures of bricks ranged from 800 to 1,000 °C, hydraulic lime was supposed the binder of the mortar with a calcination temperature lower than 1,000 °C. Damage assessment was provided and after these analyses a requalification project was proposed so the cultural heritage can play a role for the future in the dialog between different cultures.

The requalification project achieved by an integrated analytical approach defines aspects in relation to the restoration of the structures, enabling compliance with the geometry, techniques, building materials used in the original construction and allowing its guardianship and management to align with the historical context of the architectural heritage.