Lean Construction Impact on the Environmental Footprint of a Construction Project in Colombia: A Case Study

The construction industry has positioned itself as one of the main drivers for economic growth and infrastructure development in the world. Nevertheless, this industry remains as one of the most polluting, non-environmentally sustainable, and less committed to the implementation of long-term solutions for sustainable development. Lean construction, as a project management philosophy, has had a positive impact on resource efficiency and productivity of construction projects. However, there are still no several studies that have quantified the environmental impact of this philosophy. The purpose of this research is to quantify the impact of lean construction on the environmental footprint of a project. The methodology of the study consists of a comparative case study, between two projects, one using lean construction principles and the order following a very traditional approach. Both projects were assessed from the environmental perspective through a life cycle analysis using Open LCA. The main results show that there is a quantifiable relationship between the implementation of lean construction and the reduction in the environmental footprint of the project in a range of decrease between 18-24%. © 2020 American Society of Civil Engineers.Arizona State UniversityConstruction Institute (CI) of the American Society of Civil Engineers (ASCE)Construction Research Counci

The usefulness of outcrop analogue air permeameter measurements for analyzing aquifer heterogeneity: quantifying outcrop hydraulic conductivity and its spatial variability

Saturated hydraulic conductivity (K) is one of the most important parameters determining groundwater flow and contaminant transport in both unsaturated and saturated porous media. Although several well-established laboratory methods exist for determining K, in situ measurements of this parameter remain very complex and scale dependent. Often, the limited accessibility of subsurface sediments for sampling means an additional impediment to our ability to quantify subsurface K heterogeneity. One potential solution is the use of outcrops as analogues for subsurface sediments. This paper investigates the use of air permeameter measurements on outcrops of unconsolidated sediments to quantify K and its spatial heterogeneity on a broad range of sediment types. The Neogene aquifer in northern Belgium is used as a case study for this purpose. To characterize the variability in K, 511 small-scale air permeability measurements were performed on outcrop sediments representative over five of the aquifer’s lithostratigraphic units. From these measurements, outcrop-scale equivalent K tensors were calculated using numerical upscaling techniques. Validation of the air permeameter-based K values by comparison with laboratory constant head K measurements reveals a correlation of 0.93. Overall, the results indicate that hand-held air permeameters are very efficient and accurate tools to characterize saturated K, as well as its small-scale variability and anisotropy on a broad range of unconsolidated sediments. The studied outcrops further provided a qualitative understanding of aquifer hydrostratigraphy and quantitative estimates about K variability at the centimetre-scale to metre-scale