Over the past two decades, extensive research has been conducted to explore alternative supplementary cementitious materials (SCMs) in order to address the environmental concerns associated with the cement industry. Bricks, which are frequently preferred in the construction sector, generate a lot of waste during the production and demolition of existing buildings, requiring environmentally sustainable recycling practices. Therefore, many studies have been carried out in recent years on the use of brick waste as supplementary cementitious materials (SCMs) in cement mortar and concrete production. This critical review evaluates the impact of waste brick powder (WBP) on the mechanical and durability properties of mortar and concrete when used as a partial replacement for cement. It was observed that the properties of WBP-blended cement mortar or concrete depend on several factors, including WBP particle size, replacement ratio, pozzolanic activity, and mineralogical structure. The findings indicate that WBP with a particle size range of 100 µm to 25 µm, with a maximum cement replacement level of 10–20%, exhibits a positive impact on the compressive strength of both mortars and concretes. However, it is crucial to emphasize that a minimum curing duration of 28 days is imperative to facilitate the development of a pozzolanic reaction. This temporal requirement plays a vital role in realizing the optimal benefits of utilizing waste brick powder as a supplementary cementitious material in mortars and concretes.

Pumice aggregates with low density and high porosity are widely used in lightweight concrete. The high water retention ability of pumice aggregates adversely affects the properties of fresh concrete. Additionally, pumice aggregates’ inadequate mechanical strength and durability hinder concrete performance. In recent years, research on coated aggregates has gained traction to improve the physical properties, mechanical strength, and durability characteristics of concrete. In this study, coarse pumice aggregates were coated with polyester and partially substituted with uncoated aggregates at ratios of 0%, 25%, 50%, 75%, and 100% in lightweight concrete formulations. Specific weight and water absorption tests were performed on the aggregates, while slump and unit weight tests were performed on fresh concrete mixtures. SEM-EDX analyses, unit weight, water absorbing capacity, sorptivity, compressive strength, freeze-thaw resistance, and sulfate resistance tests were performed on concrete specimens. The results indicated that the polyester coating significantly increased the specific weight of the aggregates and decreased the water absorption rates by up to 85%. Despite the coated aggregates resulting in decreased compressive strength of concrete specimens, they demonstrated reduced water absorbing capacity and sorptivity characteristics relative to reference concrete. Moreover, concrete made with coated aggregates exhibited better results in freeze-thaw and sulphate resistance tests.

Calcium aluminate cements (CACs) are a group of rapid-hardening hydraulic binders with a higher aluminum composition and lower ecological footprint compared to their ordinary Portland cement (CEM) counterparts. CACs are commonly known to have higher thermo-durability properties but have previously been observed to experience a major strength loss over time when exposed to thermal and humidity conditions due to the chemical conversion of their natural hydrated products. To address this, in this study, silica fume is added to induce a different hydration phase path suggested by previous studies and utilized in conjunction with fiber-reinforced lightweight pumice to produce lightweight concrete. To closely evaluate the performance of the produced samples with CAC compared to CEM, two different types of cement (CEM and CAC) with different proportions of pumice and crushed stone aggregate at temperatures between 200 and 1000 °C were tested. In this context, sieve analysis, bulk density, flowability, compressive and flexural strength, ultrasonic pulse velocity and weight loss of the different mixes were determined. The results of this study point to the better mechanical properties of CAC samples produced with pumice aggregates (compared to crushed stone) when samples are exposed to high temperatures. As a result, it is found that CACs perform better than CEM samples with lightweight pumice at elevated temperatures, showing the suitability of producing lightweight thermal-resistant CAC-based concretes.

Every year hundreds of millions of tyres come out as waste because they fill their service period and this situation causes global problems in respect of health and environment. Today, as the natural building sand became a limited and costly material, and fine aggregate is more economical and sustainable, this lead to the usage of fine aggregate in concrete technology. In this study, rubber granule aggregate (CRA) obtained from waste tyres with 0% (control), 5%, 10% and 15% ratios by weight was replaced with the amount of fine aggregate which remains at 1-2 mm sieve opening, and mechanical and morphological properties of the samples were investigated. For this purpose, unit weight, water absorption, compressive strength for 3,7 and 28 days, freezing-thawing (100 cycles) and ultrasonic pulse tests of concrete samples were performed. Also, SEM (Scanning Electron Microscope) images and EDS (Energy-Dispersive X-ray Spectroscopy) spectrum analyses of samples were examined. As a result of the study, it was determined that the sample containing CRA with 5% ratio gave more suitable results than the other samples.

B Teknolojinin ilerlemesiyle beraber özel betonların üretimi hız kazanmıştır. Bu çalışmada, %100 kırmataş agregalı betonun iri agregasına (elek çapı 4/8 - 8/16 mm) farklı oranlarda (%25 ve %100) pomza agregası ikame edilerek üretilen CEM I 42,5R ve Kalsiyum Alüminat Çimentolu (CAC) betonların fiziksel ve mekanik özelliklerinin karşılaştırılması amaçlanmıştır. Bu amaçla üretilen taze beton numuneleri üzerinde birim ağırlık ve yayılma deneyi; sertleşmiş beton numuneleri üzerinde kuru birim ağırlık, basınç dayanımı, yarmada çekme ve eğilme dayanımı deneyleri yapılmıştır. Çalışmanın sonucunda, tüm beton numuneleri içerisinde en yüksek basınç dayanımı %100 kırmataş agregalı CEM I 42,5 R (100-CSCEM) beton numunelerinden elde edilmiştir.