The demolishing of concrete structures such as bridges, tunnels, buildings, and pavements has become a common activity due to reasons such as renovation, rehabilitation, retrofitting, or simply ending the service life of these structures. This upsurge has brought major challenges in managing construction demolition waste (CDW). Traditional demolition techniques are often characterized by high environmental impacts, inefficiency in waste management, and safety concerns. This paper critically reviews traditional and emerging concrete structure demolition technologies in terms of efficiency, safety, environmental impact, waste minimization, and material recyclability. A detailed review of manual demolition, mechanical demolition, implosion, and relatively new techniques such as static blasting, diamond wire sawing, soundless chemical demolition agents, hydro demolition, electrical discharge technology, demolition robots, and microwave heating is conducted. The key findings of this paper are that various alternative technologies have significant advantages over their traditional counterparts by offering minimum environmental pollution, improvements in on-site safety, and a possibility for materials to be reused and recycled. For instance, hydro demolition and diamond wire sawing are very efficient and accurate, meaning that actual waste management is highly improved. This paper underlines that the choice of demolition methods adapted to project needs is crucial for the development of sustainable CDW management. Such findings are useful to practitioners and policymakers who have to make fully informed decisions to promote environmental sustainability and resource conservation goals.

Among the methods of determining the permeability of concrete, electrical resistivity tests are the most rapid and one of the simplest techniques. Several studies have found a strong correlation between electrical resistivity and the other permeation properties, such as water permeability and rapid chloride penetrability. However, most of these comparisons used conventional concrete in which natural aggregates were used. Concrete with alternative aggregates such as recycled aggregate concrete (RAC) shows a different microstructure and higher permeability than conventional concrete. Thus, the existing correlations might not be applicable for concrete with recycled aggregates. This research measures the electrical resistivity (AASHTO T 358 & AASHTO TP 119), formation factor, rapid chloride permeability (ASTM C 1202), and water permeability (Germann water permeability test: GWT) of RAC. High chloride ion permeability was observed in all the samples. On the other hand, some samples were found to have low water permeability. It was observed that RAC could be evaluated as water-resistant when a low water/cement ratio was used. The bulk resistivity, surface resistivity, and formation factor were all found to be strongly correlated with rapid chloride permeability test and GWT measurements. Compared with the established correlation from other studies using conventional concrete, RAC shows a higher slope of electrical resistivity versus chloride permeability regression line. On the other hand, RAC can be assumed to have low water permeability when the bulk resistivity, surface resistivity, and formation factor are greater than 5.2 kΩ-cm, 9.6 kΩ-cm, and 528, respectively.

Placing fresh cement concrete is not permitted during cold weather under normal conditions due to the risk of frost damage. On the other hand, electrically conductive concrete can be used for deicing/snow-melting applications. This paper presents laboratory investigations to develop electrically conductive cold weather concrete (ECCWC) that can be cast and cured below freezing temperatures and has sufficient electrical conductivity for Joule heating. The concrete has additive-based freeze protection (ABFP) systems that consist of optimized amounts of accelerators and corrosion-inhibiting admixtures. Several mixture proportions were made with 0.5%, 0.75%, and 1.0% carbon fibers by volume of concrete to increase the concrete’s conductivity. ECCWC specimens were mixed, cast, and cured at −5°C. The measured freezing points of fresh concrete mixtures were below −5°C. The compressive strength development of ECCWC cured at −5°C was slow compared with the strength development of conductive concrete cured at 20°C. However, ECCWC could reach 55 MPa at 28 days of age. The temperature of hardened ECCWC increased by 18.5°C within 20 min when subjected to a potential difference of 30 V (alternating current). ABFP implemented in the ECCWC mixtures reduces the risk of frost damage and provides the opportunity to place fresh conductive cold weather concrete at ambient temperatures of −5°C without the need for taking curing precautions. The developed ECCWC introduces a new method for constructing multifunctional concrete structures to be placed and cured in cold regions.

The purposes of this study were to (a) investigate concrete pavement mixtures with recycled concrete aggregates using ternary blended cementitious binders, (b) measure the fresh and hardened properties of the concrete mixtures, and (c) assess the durability of concrete implementing the use of recycled coarse aggregates with ternary binders. Mixtures had recycled concrete aggregates at varying replacement rates. The binders were combinations of Portland cement, Class C and F fly ashes, and ground granulated blast furnace slag. At 50% replacement of virgin aggregates, some specimens showed comparable mechanical performance to the control mix. Performance is heavily tied to quality of recycled aggregates. The combined use of fly ash and blast furnace slag showed improvements in results for drying shrinkage, freeze–thaw durability, resistivity, and alkali–silica reaction mitigation.