Which forces are acting upon the screed during paving operations?

During paving operations, the screed experiences various forces that significantly affect its performance and the quality of the hot mix asphalt (HMA) being laid down.

The first force is the horizontal and vertical resistance of the mix at and under the screed. This resistance is crucial as it directly impacts the screed's ability to produce a uniform mat. A good understanding of how these resistive forces work helps in adjusting the screed's settings to achieve the desired layer thickness and finish.

The mass of the screed itself also plays an important role. The weight of the screed helps to ensure that it presses down on the asphalt mix adequately, providing the necessary compaction during the laying process. This mass helps in overcoming some of the vertical resistance from the asphalt material, ensuring that the mixture is spread evenly.

Additionally, the head of material in front of the screed contributes to the forces at play. This volume of material adds pressure and influences the flow of asphalt mix, which can affect how smoothly the screed operates and the overall quality of the paved surface.

Therefore, considering that all these forces—horizontal and vertical resistance, the mass of the screed, and the head of material—impact the functioning of the screed during paving operations,